I use CK just to know when things pop up on my credit report. They say my score is 604. We are a year into a Ch. 13 BK so this sounds about right but it has been a while since I pulled a score here to compare.
Credit Karma is about 35 points lower than MyFico for TU score. I've found that Credit.com is a lot closer than CK is and it's also a free service. But either way, none of them are true Fico scores like MF
As far as I can tell from mine, they pull from the TU report only.