The SD4 is considerably more complex. If the SD2 had a SINGLE BUTTON and a display to show the current patch, I would gladly go back to it, but I "upgraded" so I could take the SD4 out with my WX-7 Woodwind Controller on gigs and easily change patches (and see them on a display..at least the patch numbers.)
I appreciate all the weigh-ins, though. I may, at some point, find a keyboard hooked up to it and need to deal with stereo sounds like piano (which currently I don't). Now I just use Real Tracks for harmony instruments.
I just need to pay more attention when I hook my kit back up to my computer after a gig
