Maybe I can’t speak about C7 because I don’t own personally yes. I’ve used usb licence from friend sorry. My workflow under C6.5 is very complex, I Use melodyne for the vocal and choir tuning, so I need 5 or 6 melodyne instance. A lot of instruments loaded like NI Komplete Ultimate 9, Addictive stuff, BFD3, Play Libraries, all hue plugs, Alchemy, Sylent bridged because not in 64bit version yet, all PSP Plugs, Izotope ozone5, Tracks stuff, all in 64bit mode all original software registered, 3 sometimes 4 rack compressor on External Hardware routed troght RME Fireface UFX.
Reading your signature: Cubase in 32bit mode or 64bit with bridged plugs, under Windows 8.
My experience is on Mac not PC so, Melodyne crash Cubase 7 this is not my opinion, BFD3 too, sometimes C7 crash on quit. Just these things takes me out of the game 
, yes C7 is stable on mac even before if you use only some kind of plugs you are right, but I’m not ready to trash the money spent.