My bike did the same thing, ran great through mid range and into the power band but it would never rev all the way up. Thats when i checked my compression, found it was low, rebuilt and waa laa no more problems.
If you are doing that much adjusting with no results and you know that your compression is low, i would recommend that you do the top end. doing the work yourself saves a bunch of money. plus i would say do it now so that you can break it in and ride hard this summer. otherwise you may completely blow it up dead in the middle of summer riding season.... just my .02, good luck