I've finally re-installed S-Gear yesterday and played with it for a while. But as great as it sounds, I've come to develop an aversion for plug-in amp sims. Even if it sounds incredibly good, I don't think I'd be using BIAS much, so I'll save myself the hassle.
I think pretty much all amp sims have their strength and weaknesses. Last weekend, I recorded some guitar parts for a piece of music in the genre of Nine Inch Nail's Broken - huge sounding tracks, w/ plenty of gain. I had the tone nailed to perfection w/ the POD HD's Engl model. That was actually the most satisfying experience I've had w/ my POD HD so far.
On the other hand, I've been trying to tackle a certain type of smoother rock and roll sound for quite a bit, and it just won't work. Actually, I don't think anything short of a real tube amp at high volume in a big room would work 100% for this. It's not just a matter of tone/EQ/sound - that part can be taken care of relatively well - it's a matter of energy, gain, sustain, density.
The AXE FX and Kemper are both way too expensive for my taste, but a friend of mine just bought a used Eleven rack, and he's got me comparing that and the POD HD, and I truly believe that the Eleven would be a much better solution for me than the POD. If I had any money to put on amp sims, that's where it'd go.