Some people seem to experience faster alert response times with CCT. That is, they have a subscription to both, and will say that CCT gives them their alert 1, 2, or even 3 days before MF. While I am glad that somebody is testing that, I would never do it myself because it involves spending money on two different credit monitoring services.
Since you ask for the personal preferences of folks reading your post, my own preference is to use free tools only. I would not use either CCT or MF as a regular subscriber. The person I mention above was spending about $600 a year on this stuff (for the two services).
