In terms of G71 durability, I have had very bad experiences with them. I repair graphics card semiprofessionally and I reball GPUs every day. Out of the last ~20 G71 cards, at least 10-12 had a defective memory controller inside of the GPU amongst other issues. That splits up into two 7950GX2s, a bunch of 7900GTs, two 7900GTXs, two 7900GS, two 7950GTs, three 7800GS AGP G71 and a bunch of quadro versions.
I do buy most of my hardware defetctive and then repair it, so that skews the statistic, but it's still staggering how the memory controller just seems to randomly die at some point. I'm not even sure if regular maintenance and cool temperatures prevent it. If you card's picture looks like this, instead of vertical lines on the monitor, don't bother with repairs.
In my experience G70 cards are more reliable but then again I haven't had enough of those to have an informed opinion.