I have found the best expression pedal 4 SFP B2003. The M Audio XP. I have no idea why or how it works so well, but it is perfect for the B2003 swells, etc. I have Rolands, Yamahas, and even Boss. And they all sucked when it came to finessing the swell of a B3. It is cheaply built like their controllers of which I have 4, but hell nobody builds like they use to, as long as they work that's fine w/ me.
JV