64 bit will allow you to handle what ever ram you have installed on your pc instead of being stuck with the 32 bit limit of 4 gig so if you have 16 gig then 16 gig of ram is what it uses which means your are never stressing or pushing your pc and cubase to the limit , it works floorlessly here on 64 bit and to me it was well worth the move to 64bit
regards
john