Wow it took a while to respond!! Sorry. Sort of getting away from topic, but no worries.
I like both brands a lot. Great build quality, reliability, and customer service. I've owned both for years and had both companies give me replacements or repairs, with no hassle.
I was running the CA-5200 for home theater with the SSP-800 and switched to now running McIntosh MC501's for the L/C/R and an MC402 for the surrounds.
Obviously there's a single/mono amplification comparison buried within this brand comparison. I've used both B&W and Atlantic Technology on this amplification.
I like the overall McIntosh presentation a little better in my home theater. I find I can push the dynamics/volume and it is less fatiguing, and fuller in sound. That said the Classe did wonderfully. It never ran out of steam and always delivered. Vocals have historically been Classe's strongsuit in my opinion, but the McIntosh rig gives it a run for the money.I had Mac mono-blocks already, thus the transition to a Mac home theater.
I've always felt that Classe amps were a little lean in bass compared to Macs. With a good sub, which we're using anyway, no problems with music or HT, but the ever so slightly added weight of the Mac's makes for more palpable dialogue and effects in my experience.
You really wouldn't be unhappy with either. One thing I like to point out is that Mac had Classe beat in available power for HT, not so much now with the new CT/Delta amps, and configurations. FOr example the 303 is a great piece that is far more powerful than CLasse's 3200, and it is impressive, I've heard it.
Also depends on your loads. I drive Atlantic's, 6 ohm loads, and B&W's, 8 ohm nominal, but really more like 4. I feel like the Mac's, even though Classe is used to voice B&W's, are better for my ears. And I like the multi-tap options on the Mac's (2/4/8 ohm outputs) as you can hear the difference.