opinions on this will be like a certain part of the anatomy. Everyone will have one and they will all be different.
I got my first 29er about 6 months ago and have no desire to go back to my 26. I just picked up a 2nd one as a backup because if I have a issue that takes time to get fixed, I don't want to go back to my 26 while waiting for parts ect. I am 5'8 clyde. It took me about 3 rides to get used to the feel, handling ect. For me it was a very different bike at first considering I had been on 26s for 15 years and I was not sure if it was for me, but I once I spent some time on it I was hooked.
As for the wheels, you can get crappy wheel sets on anything. I have found a good set of solid 29er wheels are a strong as my 26 inch.
I have a ride buddy that feels just the opposite. He has put some time in on 29er and says they just are not for him.
If you are worried, pick up a 29er on CL and ride it a bit out on the trails you like to ride, if you do your research and buy it right, you can probably resell it and get your money back or close to it. You can then sell the bike and go back to 26, or get the 29er you really want, heck you may even want to keep that bike. If you buy it new and don't like it you will most likely take a bath if you sell it right away.
Keep us posted