I've not tried them all, but the ones I've tried I've fished pretty hard.
Thinks I've liked.
1. Breathable. They are so much lighter than the neoprene ones
2. Built-in gravel guards. I prefered Patagonia over Bailey. The line seems to get caught on the velcro straps on the Bailey waders. But then I'm a bit clumsy.
3. Patagonia style suspenders. They attach inside at the waist. This is nice if you want to take a leak, or want to wear them more pants style with the chest part down.
Now I've not tried Simms, but I think they are outrageously priced. The Gore-tex models (from all companies) should drop in price pretty soon as I believe the patent on GoreTex will expire either this year or next.
Things you should definately do. Try them with the boots your going to wear. Also, consider two pairs of boots. One for winter and one for summer. The winter ones should be larger so you can wear thicker socks (maybe even neoprene ones). I kind of like the Cabelas neoprene boots for winter. They don't have much ankle support, but they do keep you warmer. They are also pretty cheap. This of course does not apply every where. The Cabelas are also kind of nice for wet wading. If its maybe a bit cold for wet wading they may just keep your feet warm enough to make it a nice think to do.
My Dan Bailey's wore through at the edge of the knee pad area. The store did replace them, so we'll see if they hold up. The Patagonia SST+ are sometimes available for a reasonable price at Sierra Trading Post. I've heard that they don't stand up well to Deet, but I've no real experience there. I ripped mine badly on some barb wire, and could not wait for Sierra to have them on sale again. So I decided to try the Baileys.
Things still to write about:
1. Chest High, pants (waist high), and hippers
Gary Oshiro "I used to use hip waders but when I'm fishing small streams I'm often on my hands and knees or kneeling in the water and I find that my rear gets wet from the back of the hip boots."
Definately get the chest high models if your going to get float tube.
2. Neoprene vs Breathable.
Well, that's it for now. I'll probably revise this some more later.