I bought 5 mil neoprene from Cabelas in 1996 and they are still leak free!
I went to Cabela's Super-Duty Zipper Waders 3 yrs ago and have not been sorry at all. They don't leak and are far easier for this old guy to get them on. Liked this brand so much I bought a pair of hip waders too!
Now I have always been you pay for what you get! Cheaper waders don't last long.
I for one buy a size that I can get my foot in comfortable as too tight of a boot will cause you to get cold feet. These have Thinsulate in the boot and I wear 2 pr of wool socks. The outer fabric is built to bust brush and they are reinforced in the knees.
JW