I have yet to try any poly lower than 48lbs. I just find that the string doesnt snap back as much after several hours of hitting (period varies by string). I like to keep the tension right around 60. Therefore I string high around 63-65, so that it'll settle close to 60. I've even strung Firewire at 68lbs and did not find it stiff at all and plays quite lively with a little more control than few lbs lower. Firewire will settle nicely and the performance is consistant throughout its life.
Pro Staff RF97 (x3): VS Gut x/ BHB : Tour Bite : Kevlar x/BHB