I just got my GT40 today and am getting to know it. I took a break from tweaking and exploring the amp and decided to see how well the iPhone app worked. I know some folks aren't really in to that sort of thing but I was curious. Within an hour of downloading it I had browsed the on-line catalogue and downloaded about 70 presets to some empty slots. It was ridiculously easy. I was able to browse by genre, read a quick description and see what amps and effects were used (and in what order). If I thought it was promising I just hit "add" and it immediately uploaded to the amp. Zero wires and effortless. Many of the presets were quite good and the catalogue even had MIII, MII presets too. I was able to land a wide variety. Thought I throw it out there for those interested. I had no issues whatsoever with the app or connectivity. I tried the cloud presets from the amp itself as well but the app is miles beyond that approach. I haven't gotten around to using the app to tweak parameters but it looks easy enough... swipe to the amp or effects and tweak the knobs with a finger on screen. I think it would be nice to be sitting in a chair a bit away from the amp and able to tweak things without having to get up and go physically touch the amp. That's kind of perfect for how I see myself using the GT40 at times.