Not me personally, but:

See this link on a rare miss in Rwanda
http://www.fodors.com/community/africa-the-middle-east/it-can-happen.cfm

The R group in Uganda always seems to be iffy, with that reputation extending as far back as 2002 (when it was known as Hb).

To increase your odds, go twice in either Uganda or Rwanda. Which camp/lodge you are at does not matter because you meet at the Ranger Station and leave from there, regardless of where you are staying.

In Uganda, Mahinga is not as reliable to see gorillas as Bwindi.

But what I'd suggest and what I've done on each visit is book 2 or more visits to the gorillas, while I am staying in the same location. Each visit is different and awe inspiring. So is the cost at $750 a permit.

In Rwanda, you might also want to visit the Golden Monkeys, which departs from the same Ranger Station as the gorilla trips. Permit cost is much less for Golden Monkeys.

You could visit the gorillas in both Rwanda and Uganda, allowing a day's travel in between. If you have 7-8 days devoted to gorillas and are willing to spend $750/permit for several visits, you could do something like:

1 Arrive Kigali and to Volcanoes Nat Park
2 PNV 1
3 PNV 2
4 to Uganda
5 Bwindi 1
6 Bwindi 2
7 Depart Bwindi to Entebbe, long day driving
8 Depart Entebbe

It is even possible to visit the gorillas in PNV in the morning and get to Bwindi by evening, if you pick an easy group in PNV that does not take long to get to. The above itinerary does not assume that.

You'll be thrilled with your visits. Do 2 if possible. Enjoy!

It rarely happens. Bwindi has so many Gorilla Groups. Go for the Nkuringo section of the Park. am sure you will get a good group. In case of not seeing the Gorillas, some times wildlife Authority offers you a free visit the next morning.

fluffnfold, i'm sure you know this since you're researching but just in case anyone else is reading - in the example atravelynn gives she mentions the $750 permit cost but in Uganda it's still only $500. Which is partly why we are doing our two treks in Uganda.

So still $500 in Uganda? Thanks for the correction, Leslie. If planning on 2 visits, that could really sway plans to Uganda over Rwanda.

The free visit the next day if you don't see gorllas in Uganda is a nice offer, but many guests are not on a flexible schedule and have to leave after their visit.

It has been rare that the two countries are not in sync with the permit prices, so that $250 Ugandan discount may not last. Grab it while you can!

There's been talk of Uganda matching Rwanda's fee but not yet; we just bought our permits for next Feb. for $500 each. I was hoping to do treks in both countries but I just couldn't justify paying the extra.

As far as not seeing the gorillas I was wondering how often people are told they can't go because they have sniffles that day. I'll be taking every preventative homeopathic pill I can carry just in case!

I had read that about the sniffles but I didn't notice anyone checking people's health while we were waiting to go out.
The trackers are pretty aware of where the gorillas are. We were told it is very unlikely that you won't see any so we only booked 1 permit when we went to Rwanda. We were ready and willing to walk a ways but the gorillas were right at the edge of the jungle and one youngish silverback actually ran up and pushed me over!

http://kabiza.com/kabiza-wilderness-safaris/blog/those-lower-gorilla-permit-announcement-in-uganda/

Interesting, because I was under the impression Uganda was raising the price to $1000!

Wow - $1000 - would that stop people from going? Or at least limit them to doing 1 trek. I guess they have their reasons. This is certainly not a trip to put off for another year or two if anyone's considering it...

Glad to know they don't check your health status too thoroughly. No thermometers employed! Artsfan2 - I can't imagine how it felt to be pushed by a silverback - were you in total shock?!

Looks like as of June 1 2012 the Rwanda price went to $750. Did not see any change for Uganda.

I was just thinking my comment here may not be valid. "It has been rare that the two countries are not in sync with the permit prices, so that $250 Ugandan discount may not last. Grab it while you can!"

One time when I had lower cost permits for Uganda, the price increase applied to permits already bought and paid for. Seems outrageous though I could have turned them in and gotten a refund, but then no gorilla visit. So it was pay up or no visit.

Leslie:
"I was wondering how often people are told they can't go because they have sniffles that day. I'll be taking every preventative homeopathic pill I can carry just in case!"

I never saw anyone denied but I did watch porters closely watching a sniffler who claimed he had allergies. And maybe he did. His nose blowing attracted a lot of tracker/guide attention early in the trip. He took something right away and did not have trouble again.

I brought along fast food restaurant salt packets and gargled with salt water. That's something we should probably do more often in our own homes too.

That would stink to have to pay more for already purchased permits but I would if I had to. Fingers crossed they don't change the fee. I would think if it would be something effective at the beginning of 2013 we'd know by now. Maybe.

Salt water gargling - good idea too. I take elderberry (Sambucol brand of pills) at the beginning of a cold to get rid of it quickly and i'm thinking it couldn't hurt to take while we're there just for preventative. In addition to reducing congestion it's supposed to be a basic immune system booster.

Fluffn, too bad it'ss February.

Permit "specials" in Uganda for $350 for April and May 2013.Thanks to the folks on the TA Uganda Forum for this info.

I have seen a comprehensive comparison of gorilla trekking in Rwanda and Ugand in terms of costs, experience, time spent and service at http://safariadviceuganda.blogspot.com/2012/10/where-to-do-gorilla-trekking-tour.html

There is a photo in the above link of a mother cheetah and several cubs labeled leopard. That makes me suspect of any info in the link. It also lists the location of the cheetahs as Lake Mburo. I suppose that is possible, but I don't think there are cheetahs in that park. Something else questionable.

So the discounted permits in Uganda are continuing? Especially for birders who enjoy the April/May time frame, that's a great opportunity.

Back to preventing colds. Twice now that EmergenC stuff in the packets that you mix with water has prevented a cold from taking hold for me.

"Which camp/lodge you are at does not matter because you meet at the Ranger Station and leave from there, regardless of where you are staying."

Clarification in Uganda. For the most popular gorilla groups (M,the Mubare Group; H,, Habinyanja Group, and R, the Rushegura Group) that is true. The assumption was you were going to those groups.

Near Kisoro is the Nkuringo Group, a very tough trek.

Further south in the Rushaga area are two more groups: Nshongi and Mishaya.

The Ruhija region has Bitukura Group. Road transport from Buhoma is possible to this area if you don't stay there.

There is also gorilla tracking in Mahinga in Uganda. No personal experience. It has been my impression that this region is not a first choice if only one or two treks are done.

The # of habituated gorilla groups in Uganda is increasing, which is exciting. It offers More and varied opportunities for treks, which hopefully brings in more money to more local people in the area so that living, breathing, healthy gorillas are seen as more valuable than gold.

Wanted to expound on that first statement.

The road from Buhoma to Ruhija is bad...when I was tehre, after a rainstorm, there were fallen trees, rocks, etc. But the road THORUGH Bwindi Forest is terrible at the best of times. We drove from Buhoma to Nkuringo and you can literally walk through the forest faster than the drive (6 hours to walk, 7 to drive--because the road is not direct. One company (Nkuringo Walking Safaris) actually does that walk with a guide for visitors.

Apologies, I digress. Atravelynn mentioning Bitukura Group reminded me that "bit" stands for BIT by wasps. (A play on words--but the wasps are real) The area --at least in July --was infested with these horrid little insects that attack and bite for the fun of it! Use MAX repellant if tracking from there, or even just stopping on the road.

CaliNurse's comments emphasize the popularity of M, the Mubare Group; H, Habinyanja Group' and R, the Rushegura Group all in Buhomna.

I met people who did the walk through the forest from Buhoma to get to the Nkuringo group. They were delighted but exhausted at the end of their trip, really exhausted. I thought it took them less than 6 hours, but they were real hikers and that was several years back.