I picked up the AMPLIFi 150 this past Friday. This is my very first Line 6 product. I did my research and was interested in the iOS interface. I'm a total tube snob and the AMPLIFi is my first solid state amp since a Traynor TS-10 which my dad bought me with my first electric back in 1982. I also have never liked effect boards, DSPs and modelers... always sold them off and went back to pedals.
So, I was skeptical with this amp, but gave it a shot. I was totally impressed and my first run went 4 hours in my study. The amp lived up to the hype. I then read this and other posts and after seeing Rowbi's video, went out and picked up the FBV Short Board Mk II from my local GC today. It works exactly as described. The F2 button is useless, but everything else works as described. I downloaded a bunch of tones over the weekend and assigned them to the banks. It was great to be able to use the board and bank up and down then pick the tones. The change was almost instant on the iPad. Really both devices interoperate very well with the amp. I don't think I could go back to just using the iPad alone.
Thanks to Rowbi for helping me pull the trigger on the FBV. I am really enjoying this Line 6 gear.