Drive Savers, as with all credible data recovery firms, will recover information from Mac (Journaled HFS formatted) drives exactly as they will Windows (FAT, or NTFS fomatted).
A situation that might hinder that is if the user turned on disk encryption -then, if you lose a portion of the disk, you might very well lose the whole thing. This is the SAME under Mac OS X AND Windows.
Macs and PCs use the same exact hard drives in them. They both fail at the same rate, and it is equally stupid to not back up either system. The difference is that Mac OS X has a "simple as pudding pie" backup feature built right into the operating system.
I bought my first PC in 1984 and have not lost any data—admittedly, I always do backup. University IT was unable to locate a company that could retrieve said data from the Mac belonging to my friend and the external backup was not operating properly, hence the reason for the loss.
You mean Time Machine? It's so simple and yet so brilliant. :-)