I never set up the C6, I just set up with the 365C when it came up on the second hand market.
The 365C is as good as people say it is and matches the T6 timbre-wise, it's like they are from the same line up.
The T6 are a revelation for their price point. Easily outperforming the Monitor Audio Bronze 6's they replaced. They could probably do with more space than I give them but since I cross with subs it's not such an issue..