I have Hodgman 3mm neoprenes that are 5 years old and would still be fishable if I hadn't screwed up a repair [let the aquaseal on the two stocking feet touch each other while drying, feet stuck together and shredded the neoprene when pulled apart]. These things are great. As to durability and sand-in-the-boots, (i) they have padded knees so you can kneel on rocks without worrying about it, and (ii) they have built in boot guards which work pretty well.
I'm gonna get a new pair. They are comfortable to walk in, and I feel safe with them on because they're tight to the body and buoyant. They are a miserable experience in hot weather, though.
I got a pair of the Orvis Clearwater breathables. These things are the bomb. Half the price of the guideweights, which I really covet, super comfortable under all conditions, and they're blousy enough that I can wear heavy wool pants and stuff under them to keep warm. I don't like the fact that they're not inherently buoyant like neoprene, and they don't have sand guards.
I also have a pair of the worst possible waders -- so-called flyweights [also Hodgman] that are nylon. Hotter than heck in the sun, provide no insulation in cold water, don't float, don't do nothing good.