We are a dealer in RI and we have installed both TASKE and CCS. The bottom line is the best one is what you are used to...
The TASKE product (
https://www.taske.com) is made available through a company called Computer Telephony Solutions who offers the OAISYS CTI line of products. Their company includes some of the original CTI engineers at Inter-Tel and I like using their stuff because by putting TASKE in, we get the CTI server and then can run their VERY inexpensive NET PHONE client which provides for an extremely cost efficient PC phone as well as screen pop client.
The CCS product is from a company Inter-Tel bought and the GUI is a bit more easy to look at but for anyone running a fair sized call center, either product should do.
The most important thing is to find a dealer (use the dealer locater at
https://www.inter-tel.com) who understands and has experience with which ever product they quote you.
As for pure preference, I lean towards the OAISYS/TASKE combo.
Good Luck!!
ks