I have a few sets of GP3700 that I abuse the hell out of! Bought second hand from super Dan G, they were well looked after till I bought them!
Seriously though, GP may be the past, but they're the future as well. Charge at 5amps, re-peak if you wanna and discharge at whatever you like amps and around 1v per cell when you get round to it - thats what I do
p.s. I'm gonna need some more batterys soon, Dan! Got any for sale?