Mac gear "Slow" or others "Fast"

Every brand has its own "house sound" and you could call it whatever you want depending on your personal taste. I owned Mac amps and thought they were very musical but warm and laid back, where Krells are more forward sounding but not as sweet or musical. So you should pick your gear(s) depending on your taste and speakers.
Some people swear by Krells and others do the same with Mac, and nobody is right or wrong in this case.

if you have an accomadating dealer, he'll let you take gear home to audition for at least overnight. an extended listening session might give you a better sense of which sound YOU prefer. a good test is whether you end up listening for hours or if you get fatigued and lose interest. the super-detailed ('etched'?) sound can have a certain "wow" factor but may not be your cup of tea over the long run... it sounds like you're unsure of what it is YOU like and you'll be better able to determine this if you can audition the equipment at home, with YOUR room acoustics, and YOUR other components. hi-fi showroom demos are only useful up to a point!

i have owned both mac and classe gear and i wouldn't call mac gear slow. i would think it would depend on the amp and speaker combination. i have heard the larger macintosh monoblocks (1000's), the mc352 and mc500 driving the larger snell and krell speakers and they were not slow. i used to own the mcintosh mc202 amp and the ma6500 integrated. when using these pieces with my totem mani 2's, they didn't do the speakers justice. when i demo'd the mcintosh mc352 amp with the mani's, it was night and day difference. the 352's had the power to drive the mani's. i used to own classe gear (ca200, cp 47.5, cdp 1.5) and i would say that the classe gear that i have heard/owned sounds very similar to the mcintosh gear i have heard/owned.
i agree with nickt above, it is all about personal taste.

linearity is mac's signature. they favor no frequency. the result is a very neutral presentation. their tube amps are the same. of all the solid state gear in the marketplace they are more suited to long term listening than auditions. if the recording has it, they reproduce it. they add nothing.