My CK score (based on the TUrisk score) has been perfectly logical for the last year - it has steadily increased from 730 to 780, as my util has stayed the same and all last years accounts have aged and I have had no new accounts and no inqus.
Unfortunately, logical as this is, it bears no relationship whatsoever to what has happened to any of my real scores!!!!
I've found that the simple estimator on this site here:
comes about as close as any of the FAKO scores, and it's totally free.
Interestingly enough, my score at creditkarma is about 50 points lower than the score at myfico... And unfortunately, the official tally by a lender mirrored the creditkarma score almost exactly... So I dunno.
I use creditkatma to find out if certain info has been reported to TU. Heck it's free. It is perfectly accurate if you really want the TU Risk or Vantage score but it does not report FICO scores.