I am using a clone of the CS2, with the same driver line-up
The Selenium DT220i tweeters are extremely sensitive for the right or wrong amp.
I started by using a T-amp with the tweeters but that sounded horrible.
Currently I am using a SET 300B amp for the tweeters, and the results are very good: clean, open not harsh.
The (quality of the) amp for the lows is not (extremely) important, any good powerfull amp will do, although there is some difference ofcourse. I have been using a Behringer EP 2500 and EP 1500 with great results.
It is no problem to get a well integrated sound using an transistor and a tube amp, although it might cost you some extra time to get the levels set up properly, and use some extra EQ, which is no problem with the DCX.
There is no need to use identical amp, on the contrary