Interesting. I picked up some USynths and although they are not my top-line / go-to prefered synths, I have enjoyed playing around with them and have found them useful for some music I enjoy doing. I can definitely see their appeal.
Having several USynths, I have wondered why UJam didn't give credit with the USynth Bundle for previously purchased Synths like some music software makers do. (Maybe it was there, but I never found it.)
Not sure I want to pay double ($19 v. $9 per synth in the Bundle) to fill in my collection just to have all the current USynths, but I think it's the next best thing. Maybe if APD does well with this promotion, UJam will consider doing a pro-rated fill-in-your-collection loyalty deal for users interested in the bundle based on how many products a user already owns.