Anybody with some thoughts on Hafler amps

Recently I picked up a Hafler 9300 amp along with a Hafler 945 series pre-amp. The (used) amp and pre-amp were purchased to drive a couple of Dali Euphonia MS4's. During the first hour or so of listening, the amp seems about as musical as a brick; when performing numerous comparisons against a Denon 3805 A/V receiver, the Denon had it beat all to Hell. However, after an hour or two of continuous play, some voodoo magic begins to happen (I know the amp warms up) and the amp begins to gain some essence and hence forth the music starts to flow, not sounding starchy or flat…I guess to get to my point, has anyone else with this amp or something similar had this experience where at the beginning it’s almost intolerable, and only later something decent occurs? In addition, if anyone else is driving some Dali speakers I would be curious to hear what types of amps you have used and some of the lessons learned. Musically I’m all over the map: The Rolling Stones to Rossini, Fats Domino to the Lords of Acid. Thanks for any comments. Cheers