I am starting to plan a vacation for next spring (late April-early May) I would like to go somewhere with a lot of natural beauty and plenty to keep my wife and I busy for a 10 day vacation. I would like to travel to both Hawaii and Arizona, I have never been to either one. I would like to hear from people who have been to both and have them tell me their preferences and which they would think would be better considering I only have 10 days.

The type of beauty is VERY different between the two area.
The convenience/concentration factor varies significantly.

The Hawaiian islands, to me, provide the ultimate vacation getaway. Exotic island beauty which is not exceeded by any island in the world. Great variety from Kauai to Big Island to Maui to Lanai to Oahu. All quite different from one another. The best concentration of top notch resorts in the world. Great food options, outdoor activities, a wonderful relaxed atmosphere (with a couple exceptions)...it's all right there.
So Utah/AZ provides stunning natural beauty, a big part of which is due to the sheer size of the sights. The open spaces are simply awesome and unspoiled. BUT, requires quite a bit of driving to get from place to place. Hours and hours at a time. Scant lodging options and infrequent good restaurants.

Would I attmept to do both areas in 10 days? No way. You'd eat up a third of your trip travelling between target destinations.

Either trip would be wonderful for most travellers. The southwest is certainly a whole lot cheaper.
But for overall enjoyment, variety, quality, and memorableness, I'd recommend Hawaii. (BTW I've been to Hawaii many times and used to live in AZ).

I'm sorry if I wasn't clear. I didn't mean that I would like to visit both of them within the same ten day period, just that I would like to visit both. I will be coming from the east coast, so I was trying to take time limitation as consideration. Thanks Gary, I found what you said very informative.

Have not been to Hawaii, but have been 3 times in the last three years to So. Utah. My question to you is: how do you and your wife like your natural beauty? Do you like it framed from the door of a 4-star hotel, or do you like to be out on the trail, taking it all in? We are outdoors people, so Southern Utah/AZ fits us to a tee. As long as there's a hot shower and meal at the end of the day, with a room with a bed & clean sheets, we're happy. If there's a little ambience & good drink added to the mix, all the better. As Gary points out, there aren't that many 4-star lodging/dining opportunities in So. Utah/AZ. Many times, it seems to me that people are disenchanted with the visit to Bryce/Zion/GC because the lodge settings are not "luxe" accommodations. If you'd like the ability to upgrade to truly fine lodging and meals, I think Hawaii would be the perfect setting for you. Good luck in making your decision.

Something to consider:

Being the type of person who would gladly hike ten kilometers in blazing sun order to great shot of an overlook or waterfall; the desert Southwest has always been a favorite of mine. I love all of Utah's national parks, and I've been to the Grand Canyon six times (twice to Phantom Ranch). But there's something to remember about this desert beauty: there pretty much NOTHING except this isolated desert beauty. No historical sites (except Anasazi ruins, which are more archeology than history). No cultural attractions. No night life. No museums. Not really that many PEOPLE (which is an attraction to me, but others may not like the idea of emptiness).

Hawaii has great beauty -- and much more compact, as noted previously. AND culture. AND nightlife. AND museums. AND historical sites. AND places to just relax and do nothing for hours. If you feel you've seen enough nature for a day, you can do something else for a change. You can't do that in the Southwest -- if you don't want desert beauty, you can't switch to something else.

Unless stark desert beauty is a real attraction for you (it is for me), I'd recommend Hawaii over the Southwest.