trouble with Apple's FileVault

Going back as far as Panther, Apple has built in a security tool called filevault which promised to be an alternative to third party encryption programs. The problem is in many cases it does not work well. Of the 100 or so laptops we have enabled FileVault on 5 have had problems with dataloss, being unable to disable Filevault, and slow performance. Apples own tech support have confirmed that file vault is problematic and they dont recommend using it. Truecrypt is a good alternative.