grades and learning new peices

[greyrune]

i was wondering about how long it should take you to learn a peice of a certain grade before you can consider yourself of that grade level.  I can play some grade 8 peices but so far they have taken me quite a while to learn (5 weeks plus).  However i just learned Allegro Barbaro by Bartok (cool peice if you want something a little angry) in three weeks, i don't know what grade this is but i assume it's easier.  So how long should it take to learn a grade 8 peice to be a grade 8 player.  I mean i've heard many people on here talking about amazing peices they've learned after a year or something but i'm guessing it took ages to learn.  On a side note about how long should it take to get to grade 8?

[lagin]

Grade 8 RCM?  or grade 8 ABRSM? 
Learned meaning notes learned and up to speed or meaning notes learned, up to speed, and memorized, or meaning notes learned, up to speed, memorized, and played musically to the point where you are satisfied?  Also, during this 5 weeks, do you work on anything else? 

Grade 8 RCM, to get the finished product, many people spend one year in this grade, which includes learning about 4 longer pieces, 2 shorter pieces, and lot's of side stuff like scales and eartests.

Grade 8 ABRSM, i'm not sure, but it's much harder than grade 8 RCM. 

[greyrune]

I meant ABRSM, and yeah up to speed, memorised and, well, musically so my teacher reckons it's good enough (can anyone ever play anything so that they're completely satisfied?)  So far no i haven't tried working on more than one peice at a time, i really should i suppose it just seems a bit destracting.