I swapped from a 7R to a CS as I wanted a more exclusive and much rarer car and I don't regret it at all. My CS has DCC with 19s and I need to keep it in comfort for most of the time. My 7R had 19s and no DCC and I didn't have any problem with the ride quality. Does the CS have firmer suspension than a normal GTI, I seem to recollect it does? Given my experience, I would definitely specify DCC on a TCR due to the firmer suspension.
Disappointingly, given its touring car heritage, it really is a shame that the TCR does not have bucket seats, CS rear spoiler and a different exhaust to make it that bit more special. That said, because the spec doesn't really overlap with the CS, it means that CS will remain a sort after car with its own unique very desirable spec..
I certainly wouldn't swop my CS for one, but I would buy it in front of a GTi or an R due to its exclusivity. The TCR will be a rare car and I reckon it will be pretty sort after in the used market a few years down the line.