Although not exactly the same issue, you should read my theory on pet scaling:http://eqiiforums.station.sony.com/eq2/board/message?board.id=30&message.id=16634
From adept 3 to master 1 there should be an improvement in performance, though. Exactly how does it seem less powerful? The only way to say that with any fairness would be if you could provide a parse of how much damage the adept 3 takes versus the master 1.
I do not parse myself, as I do not wish to play at that level. But if anyone else wishes to provide such data I would like to see it.