Hmmm. I've got a pair of M22tis in a roughly 12x12x8 room and they are plenty detailed and "present" at any volume.
I don't think the integrated amp is at fault, since it can clearly drive the speakers louder than you like. If it were really making your speakers sound bad, it's a poor design and you should return it. We here on the boards like to believe that most amps do not color the sound of speakers to a degree that's very noticeable. And, ideally at least, this should be true of any decent amp on the market today.
Anyway, could you describe your listening space and how you have your speakers placed a little more? Is it a spartan arrangement with lots of hard and reflective surfaces, or more of a soft environment with cushy furniture? Are your speakers close to the walls or placed more out into the room?
All these factors contribute to how your speakers sound. With some tweaking, I have a feeling you can greatly improve your enjoyment of the M22s. There is a possibility, however, that you just don't find the sound of the M22s appealing.
