wow, did I expect this many responses!!! Thanks!

Our English and Scottish friends arrive in the US with cases as large as steamer trunks.

Americans on this forum are generally fanatics about traveling for months with only a carryon bag.

As you can see, there is plenty of room for "advice" on this spectrum!

I think the only thing that is a really bad idea is trying to manage two rolling cases. Ask me how I know this.

If you travel by public transportation but are not changing locations every night by, a mid-sized bag but not carryon bag (25-26") is nice and not difficult, particularly if you initially load it only with what will fit into a 19-20 inch bag.

I have been travelling regularly to Italy for 20 years with varying sizes of rolling suitcases, some very large, and have never had a problem. This includes trips where I travelled on my own (as a not very large/strong woman) and trips by train. Just leave your luggage in the areas at the end of each carriage (like the locals do) - no need to manoeuvre it along any aisles. Like someone else said there are a few steps up to the carriage, but no difficulty other than that. I have never paid anyone else to help but sometimes kind (larger & stronger) fellow travellers volunteer. I find one large bag easier to deal with with 2 or more smaller ones.

Personally I can't manage more than a 2 night trip with a carry-on size bag. It's not even so much the clothes - before I add any clothes my case is normally at least half full with shoes, toiletries, odds & ends of hardware and particularly books.

I am planning to take one 21" and one backpack on my upcoming trip to France for 3.5 weeks. Now, whether what I want to take will fit into it is another story. I just bought a new 21" "super light" suitcase at Costco.... My old one (a favorite 22") weighs 12.5# emply; this one weighs 7#.

It's those darn trains that make me pack light. I just can't lift things that heavy. If I took only cases I could lift, I would be taking only a purse! :)

I've traveled on trains in France and Italy with a 24-inch carryon. No problem.

The other problem with a largish rolling bag on trains is when you change trains. You may have to drag/carry that bag down one set of stairs and up another set to get to the proper track. So it's not just the few steps up into the train.

And you may think you've planned a trip with no change of train, but plans may change when riding Italian trains. Strikes happen, breakdowns happen.

It also depends on how big YOU are. At 5'3" and 112 lbs., even though I'm pretty strong I can't manage anything more than a 22" rollaboard easily. Nor do I need more clothes than a 22" can carry, even for an extended trip. I just don't want to spend my vacation being a sherpa.

Several years ago I took a group of teen girls to Europe. I told them 22" ONLY. Of course only ONE girl was able to understand that and think the rule applied to HER. So, the day we had to change trains in 8 minutes in Switzerland I told them "good luck". It was funny watching them try to get that huge luggage off train one, down steps, up steps and onto train 2 in the 8 minutes. (They made it, but the adults did not lift a finger to help)

After we got on the 2nd train one fo the worst "offenders" said to me "I AM NEVER BRINGING THIS MUCH STUFF AGAIN"

And honestly, I could not tell you a difference in the "wardrobe" of the girl who did have the 22" and the girls with the steamer trunks.... So.. packing more didn't make them better dressed :)

I can't travel light no matter how hard I try. Every city is full of friends, relatives and acquaintances and they all wait for gifts....and then I shop. A big rolling suitcase (BIG....like 100 lb capacity) is my way of life, and they fit on Italian trains just fine. There's usually sections for the large ones and an overhead spot and on the overnighters there's even space under the seats. Of course at times I've had so much that one suitcase rode on a seat or in the corridor, but hey, such is life. The worst that ever happened was a dirty look or 2, but Italians are really nice and actually more inclined to help a girl who weighs less than her suitcase than any other Europeans I've encountered (except Norwegians-you're all perfect gentlemen up there, and thanks for all that help with my luggage years ago). Another thing about big rolly bags; Italian trains and thieves go hand in hand. If your luggage is awkward it's a total thief repellent and an excellant idea :)