I do think BIAS FX 2 is quite a bit better. I don't really know much about programming but I get the impression their software is built on a not-great foundation.
I think it sounds pretty dang good personally. I just wish it worked better in my DAW. I have to open every plugin window in the session before it will work. Also can't monitor through it in studio one using low latency monitoring for some reason.
I always wonder why there aren't non-proprietary outboard DSP unit. Seems like the ability to run VSTs from multiple vendors would have a serious market.
I really like it. I also have Amplitube. Part of me prefers the 'actual' amp controls like Amplitube but Bias FX sounds quite good. (For the record so does Amplitube)