I did not try Mandrake 10 (used 9.0, 9.1 and 9.2 though) and from my point of view, Mandrake is superior(from a point of having a wider community) and easier to use. SuSE (that I'm using now) is quite pricey for what they offer. YaST is good, but I still prefer Mandrake Control Center: So much better to start and stop services. YaST update not always work, unlike Mandrake Update.
Mandrake, in another hand, seems to enjoy coming out buggy. 9.2 was worse then Win95: Menus dissapearing, evil-kernel which destroys LG CD-rom players, etc. It took a while to get those problems addressed, but after that, it became a very good distribution.
I think both are pretty much on the same level, but with SuSE being less buggy, and Drake being easier to use...
If you want to invest cash in one distribution (as you would with SuSE), I'd recommend Libranet:
really nice, fast, 100% Debian compatible and offers a nice tool (adminmenu) and even 3D hardware acceleration out of the box for supported cards.
The choice is yours padawan