In the very least, especially since you have a VTF-2, you will find the CBM-170 comparable to the Studio 20.
A few people have compared the CMT-340 to the Studio 60:
http://www.ascendforum.com/forum/topic.asp?TOPIC_ID=199
if you can, I suggest you order a pair of 340's to compare against the Studio 60's.
-curtis