Hi stevenmat,
Practice CAT scores are only as realistic as YOU make the process of taking the CAT. The more the 'CAT-taking event' deviates from what you'll face on Test Day, the more likely the score is to be inaccurate (and in most cases, that means "inflated").
When you took your CATs:
1) Did you take the ENTIRE CAT (including the Essay and IR sections)?
2) Did you take it at home?
3) Did you take it at the same time of day as your Official GMAT?
4) Did you do ANYTHING during this CAT that you couldn't do on Test Day (pause the CAT, listen to music, etc.)?
GMAT assassins aren't born, they're made,
Rich