Anyone have much experience with them?

I know primarily this is a hardware forum, and I usually deal with hardware issues, but I have a personal favor being asked of me to recover some data from a drive that gave some grief.

Apparently he upgraded his linuix distro (Ubuntu) and the LVM volume wasnt recognized. He freaked (all digital pics on this VG) and tried to reinitialize the VG with another set, thus he overwrote the LVM data. The raw data is still there, I have successfully recovered a lot of his data already, the problem is, there is a large (many Gigs) section that is not working for me.

Any ideas?