In terms of top teams (teams that have LAN winning potential)
Americas>EMEA>China>APAC
I see G2, and SEN being the favorites to win events but I also think Americas has more teams that COULD win, Heretics and Vitality from EMEA are really the only contenders I see really. I don't see how any APAC team is on the same level as the above mentioned. however, I can see EDG running it back, however that's just one team from china so they are below the teams with multiple contenders.
In terms of league quality (top to bottom, how well are the rosters built)
EMEA>APAC>=Americas>>>China
I feel like this needs to be justified a bit, Apeks is fairly easily the worst team in this league (I think their tactical prowess clears 2game and mibr), but looking at the next best team, KOI (or GX) I believe these teams are much better built than 2game, mibr or eg. APAC. I think zeta is pretty easily the worst roster in APAC, I think this matches up pretty well with americas, I think pacific and americas are fairly equal, however I think the 10-6 of APAC is better than the 10-6 of Americas.
Not to comment on who has the better league but i feel like americas has the most winning potential, but overall their league top to bottom was built fairly lackluster