I only just got the Corsynth Dual Looping VC AD this weekend, but it certainly warrants a look given your interests. It comes close to 281/DUSG functionality in 5U. Not exactly the same but similar with +/-'s both ways. As mentioned above, it has some nice i/o with two outputs for adding/subtracting the waveforms, and trigger switches for longer or more complex shapes.
I also have a pair of Oakley VRG's which are similarly snappy and have slightly different features. I've had them for a long time and they work well also, of course. Both are flexible and add a lot of other utility to a small system.With both modules, I might suggest keeping a Multiples module close to better approximate banana jack patching. At least to me, the modules kind of beg for it so they can be patched together and still have outputs free.
Even if you mainly want to use AD shapes, you might enjoy a full ADSR in your arsenal from time to time. Particularly since they can also do AD, and the Dotcom ones are usually only $75 used. VC ADSR's are nice too, but in reality the VC AD's cover much of that ground.
I guess I'm a little addicted to envelopes, but I suggest giving yourself a few extras to play with. Mixing two or more can create some really great results.
EDIT: Missed your last post. The CGS DUSG is a great pick as well.
