I also heard that the Asus mobo is more stable, but the DFI is more overclockable, is this also true?
Yep... that's right. My Asus A8N-SLI Premium doesn't really overclock for crap (I can squeeze about a 25Mhz FSB OC on it). But it's stable as hell at stock speeds.
If u really wanna OC, the get the DFI Lanparty series and buy some Corsair memory.