Thanks for the link to microtonic Loptec, that certainly ticks all boxes as far as an electronic drum synth is concerned, and I reckon I would certainly use something like this over the sampled electronic drum sounds available in Battery, for instance. I will probably have this added to my arsenal by the end of the day, if not sooner.
Last night I purchased Chromophone. I've not had much of a chance to play yet, and I experienced an unfortunate X1 crash while trying to drive Chromophone with Step Sequencer. Prior to that, I was also experiencing some crackling problems, and I didn't have time to determine if it was digital clipping, audio interface settings or just part of the Chromophone patch/sound. It didn't happen in every preset I tried, but it was still a bit worrying non the less. Some time today I will be doing more "tests."
What an excellent topic this has turned out to be 8^) for me in any case...
edit: Oh, I've just spotted the reference to the fact that it is only available in 32bit flavour at the moment, so I might have to hang on till the 64bit version comes out...