Well, have a quick look at asarkila's scores on level 43 (jungle). I glance at the games played and hope he gets through, but it's a very tough level .... in fact I believe Wil N Wil (teamwork) is stuck there. As for me, I've managed the Jungle road so far and figure the hardest level left for me is Reef 80 (no disrespect to Mountains, but at least Mountains are based more on method than chaos).
Level 80 Reef is pretty much a Jungle level that's a little harder than the Jungle 40s, but not that much... and has much method to it (but still much luck). I now have 5 scores over 1000 and have come within 50 gems (of 1500) of getting enough - it's only a matter of time. And it's a fun level.
Well time to give ti a couple of goes... but after the Christmas party there's not much chance.... but I'll see how drunk I really am before heading on later.