I personally think advanced RP should refer to the writing quality and depth, with post count being a likely indicator.
And this quote below was referring to an RP in which the opposite occurred, where post count took priority over depth and especially writing quality.
[quote=Tydosius]
I checked out an advanced RP once. It just kinda turned me off advanced RP completely. So I'm not sure what to say.
[/quote]
I should check out more advanced RPs to see the bigger picture.