The only major problems I have heard so far was a bad batch of H100s where the fan controller prematurely failed on some units. However this has since been resolved. If you're still worried this is the specific batch that was affected:
As for push pull with the H100 you aren't going to see huge temp differences mainly because the H100 has quite a lose fin array. A lot of people seem to recommend the CM blade masters because they're cheap and they're quiet and output a lot of air. Only downside is that they don't last as long because of their sleeve bearing but at under $10 at most stores it's still a good value.