IMHO, with the qualifier that how populated the world is makes a big difference:
D3 southeast can be easy because of the lack of schools down there. Michigan / Wisconsin in full conferences is the toughest.
D2 is the same. South east recruiting can be very good. Northeast in empty worlds is good because of lots of recruits close with no human competition. And I mean upper NE, not like NY area. Northwest in empty worlds can give advantage, but in a strong Cali and Great NW, you'll have problems.
D1 really varies by school, not area. Just look at big 6 schools with average baselines that are always successful and you'll know where the honey holes are. For the most part, MWC is a good spot because there's still quite a few recruits youll have distance advantages on and you are really only competing against the PAC10.
I've never really understood why people don't try to power up the A10. Sure it's east coast, but good locales with competitive baselines. Instead i see guys trying the ivy league or nec. Perhaps someone can explain it to me.