Mahela not consistent? That's a bit harsh, I'd say he's been very consistent in the last 4 years. Actually if you look at it the only place he really messed up in the last 4 years was 2 tests New Zealand. He performed ok in England; nothing special but he did save a test there. People do underrate him due to his away record, which he does have to improve, but it's not as if he's had many chances, since 2006 3 tests in England (where he got a 100), 2 in Aus (where he got a 100) and 2 in NZ. I guess we will find out next year where he sits with the very best.
Migara I would have to disagree with you about PJ playing spin better than Mahela. I don't see it that way; PJ only looks respectable against spin because comparatively he looks so hopeless against pace. He does have some decent attacking shots, but does not have the ability to manouvre spin around like Mahela or Samaraweera.
For me Mahela is the best player of spin in SL team slightly ahead of Samaraweera...both have good footwork against spin and can attack or defend against spin well.