The DM12 is a good synth. On the plus side it does sound great. On the minus side it has (fairly quiet, thankfully) fans and I found some aspects of the architecture a bit restrictive.
For the money - you can't really go wrong.
If this one appeals then also take a look at Roland's System-8. That's a fabulous-sounding synth, only marred by a plastic case (with external PSU), short keyboard and lack of aftertouch. It's quite a bit more expensive than the DM12, but it's a more fully-featured synth.