I was excited about the GT-1 until I demoed it with a bass. It seemed very tuned for guitar and had a bunch of modeling that I wouldn't want. It looks like the MS-3 has the GT-1 effects engine, but they added bass-specific versions of some of the effects (T-Wah, Wah, Harmonizer, Octave, Overdrive/Distortion). For example, I tried out the T-Wah on the GT-1 and it really wasn't responding well to my bass. In the same store, I plugged my bass into a Roland Bass Micro-Cube and the built-in T-Wah effect reacted great and sounded good. I like that they also ripped out the GT-1's modeling for the MS-3. I am seriously considering getting this. I currently have 3 pedals (octave, overdrive, delay) and a Boss RC-1 looper. This could replace my current effects pedals, add extra effects, and allow for expansion in the future via the effects loops.