The way I see it there are 2 types of compressor, there is the Stompbox which is about 10db max, cheap and good for messing with. Or there is the rack comp. Basically if you are looking for a higher quality compressor than the CS-2 try the dynacomp, if still you need more you need to look at a rack comp, in which case I suggest the dbx 1066 Dual Compressor Limiter Gate, it is a good comp to start your search.
Yup, the barber compressor is one of the most transparent compressor in the market. If you pop by to the many of the US forums, it seems to garner more reviews and thumbs up than the Keeley. Keeley will colour your tone, though in a beautiful way.