Am pretty kicked about this. I realized that encrypting files/folders is good but windows leaves too many traces. And the biggest reason was, I don’t want to worry whats on/not on my HDD when it craps out, So the choice was between PGP, TrueCrypt and Bitlocker.
I went with bitlocker and till now, I’ve zero cause for worry or concern. Its pretty seamless and truly amazing. People say that one takes a 10-25% hit with encrypted HDD’s. I don’t know if its true, as things seem just as they were before encryption. One thing though, data transfer has slowed by 1-2Mbps, which is not a big deal for me.
I don’t have a TPM (actually I should have one but I don’t, weird) so I went with the USB stick authentication. One reason I liked bitlocker was the recovery key (48-digits) can be printed on put in a file, this is critical stuff.
Bitlocker doesn’t encrypt the whole HDD; you have to start with the system partition and then move onto other partitions. Its pretty smooth stuff. And of course, for precaution you should turn D+ off. 
Loving it… :-TU