I'd give the edge to Miami because young teams like the Thunder don't win championships normally. Unless you're Magic Johnson, you kinda have to be stepped on a few times.
The Thunder are not the well-oiled machine that Dallas was during last season's playoffs. Yes, they got more experienced, and will probably make it to the Finals(shouldn't say probably. Who is their best competition? The Clippers?), but I just don't see it ending pretty.
I'd say Miami in 5- it would be similar to last year's ECF. Thunder would blow the Heat out in one game, but Miami would prove to be the superior team in the other four.
OKC has a ton of young talent but they still haven't come close to meshing. I don't know that they will. But if they make it this far it means they will have put a few things together. I still don't see them beating Mia though. Mia in 5. Possibly 6 depending on how home court works out.
I still don't believe in the Thunder until they get rid of Russell Westbrook. The guy is absolutely dreadful at end of games, and he even showed against Minnesota today that he was ballhogging it today.