I've never thought about using CPSTAR or CASTAR tickets to maximize segments, but I do tend to use them to hit a cluster of cities in each of the regions on routes that can be painfully expensive. In fact, I now leave at least 2 open at any given time and come back and pick them up later (typically leave one in NASIA and one in SASIA). I used to book these trips as a sequence of widely expensive one ways (try PEK-ICN in C) and then learned about the circle fares- no thanks to my corporate travel agent of course. I have one CPSTAR2 parked in N Asia now with enough miles on it for a 4 country set of meetings in N Asia and am starting up a CASIA ticket and heading down to Aus/NZ. I find ways to squeeze all the miles out of them, but in reality for me the value is having an open ticket in NASIA and SASIA that I can pick up on a moments notice and use to cover some routes that would themselves cost almost as much as the entire ticket.
The additional "value" for me is getting to pick NZ across the south pacific and SQ across the north, as well as the NZ flights ex-NASIA. That is priceless!