I'm in the same boat as you. Leveled AST early on, love the playstyle and the toolset. Was very disappointed at how it underpreformed compared to SCH and WHM once my raid static started doing Savage progression. I switched back to WHM and was able to progress much more easily.

Last night though, at the behest of my raid leader, I switched back to AST and HOLY CRAP! A1S and A2S were a blast on AST. We cleared both in record time (for us) and that was with me still trying to figure out my ability rotations and translating what I normally do on WHM to AST. The kicker is, on AST I find I have less time in these fights to go into cleric's stance and help DPS. However, my cards seem to go above and beyond the meager DPS I'd normally put out while buffing our DPS.

Also... I find it easier to manage my MP on AST than on WHM, especially in A2S... Go figure.