I've been playing several chars on eu rampage/blackout/cataclysm, and i've been playing on eu-hinterhalt (which was called eu-nemesis beforehand), and what I found out was that there are less people at very high rating on huge/good bgs that do not 'deserve' their rating, while there are a lot of people that are simply bad but playing fairly/really high, thanks to their class/comp mainly, on bad/poorly populated BG.
Although it's pretty equal since on poorly populated BGS, you will chain queue into the same team 4-5 time, and generally means that if you counter them (for instance win 4 or 5 games out of 4/5) they will probably stop queuing, and you will queue into 2k2-2k3 people, that are not worth it. While on bigger BGS, you actually get the chance to face multiple teams that have a mmr which is often close to yours.
There also are many people that xferr to "bad" bgs right before the end of the season, to give a shot to "easy" rank one. Many of these guys actually fail really hard and xferr again though.
TL;DR : yeah poorly/moderately populated bgs (hinterhalt, charge, vengeance, frenzy, emberstorm, reckoning) generally are "easier" to get rank one on, but these bgs tend to get a lot better at the end of the season (because of all these people xferring there for glad/r1).