really?
Ive played all the other MMOs out there and quality isnt much different. Theyve simply invested in different parts of their MMO. Some dont have raiding, others invested in massive PvP worlds. Others invested heavily in story and questing.
This idea of quality is totally subjective, afterall Wow looks the most out of date graphically than all of them yet that doesnt effect their subs much.
Basically there isnt much difference in quality between F2P or B2P games to Wow or Eve, who are pretty much the only paid subs MMO games out there right now.