The Axiom and Ascend sound is very similar as well. If you like one, you'll likely enjoy the other.
As far as "brightness" goes, I had a guy over the other night to demo my system. He LOVED the M60's and brought up the "B" word. He said he was surprised that they were indeed NOT bright. He also noted that if there were going to be bright, they certainly would sound it in my room, as I have hardwood floors, and very little on the walls yet. (recenly moved)
He too was not going to be purchasing a subwoofer right away, so we did our listening sans my Hsu. I must admit I was pretty surprised myself at the amount of bass the M60's can produce. A good sub is still needed for movies, but for music (even some bass heavy stuff) the M60's were more than enough.
