gs, you didn't say what you intend to do with the CAP10C. If you want a nice tourer that you can do gentle aerobatics with, then it is a great machine. It is OK as a regular aerobatic mount, but does have fairly low limits which must be observed rigorously.
The C wing has strips of carbon fibre on the top and bottom of the spar to reinforce it.
The 10B is just wood and some have suffered from stress fractures, particularly when old and overstressed.
The general opinion is that the C wing is OK.
Flick manoeuvres stress the rear of the fuselage and the 10B and 10C are the same here, so its important not to exceed the flick limiting speed. Unfortunately, a recording G meter won't let you know this.
It isn't as strong as a Pitts or Extra and isn't as capable aerobatically, however it is a more comfortable tourer.
So, the decision comes down to what aerobatics you and the other owners perform. If you are all wanting to do flicks and gyroscopic figures and very little other than aeros it might not be the best machine.