Ross, I fiddled around with Bias and Jamup Pro XT for some time. It does sound great and also feels good, much better like most cheap modelers. However, it has glitches, esp. when switching from BIAS to Jamup and vv. The latency is one of them: when I play in one app only, there's little latency, when I switch, it increases. A lot of the latency issues with BIAS are related to the interface. Apogee Jam seems to work fine for most people, iRig, Griffin Stompbox and other cheaper ones don't. I have a Roland Duo Capture EX that is very comfortable and also supports MIDI which is nice. It works well. But I also wouldn't dare to use the iPad-based modeling live. It's too fragile, both in build quality as well as in stability of performance. But I think BIAS is the first app that really can compete with stuff like the 11R. Also the tweaking options are extremely detailled and much more realistic than in simple modelers (including the Fender Mustang, which I own as well), where those options in most cases feel more like drastic eq changes rather than like realistic tweaks to an amp.