I haven't been in a B3, but we have a couple of FX2's as well as a Soloy. The FX is certainly my favorite. We've been working at sea level, but the temps have been as high as 100F and 80% humidity and it'll still lift 1800lbs off the ground with 50% fuel. Slowly, but it does it. This is at 93% TQ, just touching the yellow on T4.
I think the main advantage of the FX2 is the maintenance. It's very simple, not nearly as many electronics to fiddle with or worry about. We went 600 hours without any major issues at all, and not a single electrical issue.