I am glad you asked. I have the same basic question and there doesn't seem to be a lot of info out there that I can find. There are hardly ever any used ones for sale on this site. Is it because they are so good or so bad? I do see that Magnolia Audio located in the Best Buy stores (that oughta make some Gonners cringe) now carry Def Tech's. I/we should be able to get a good listen to them there. Getting a shot at listening to some equipment nowadays is sometimes a difficult task since most stores don't carry all the models. A listen beats ten opinions any time...Good luck!
-John
-John