Is the sound quality of bryston 7 much less than..

Is there a significant comparison between the bryston 7 monos and other high higher end amps. Like Pass, krell, mark levenson etc. Hope someone can tell me their experience. Presently driving magnepan 3.6. I think they sound great but the grass is always greener on the other side.
At this level, there isn't much of a real difference. Side by side, you could likely hear something. Or, if you replace an amp you've had for a while, you could probably tell there's been a change. The best thing to do is go for a listen or arrange for a home audition. You have to decide for yourself if these differences are worth making a change.

I recently replaced my Bryston 7B ST's for a pair of Pass x600's. The Pass' seem more delicate and detailed, with notable liquidity and purity in the midrange. The Brystons seemed stronger in the bass, more substantial or in-control -- functionally slightly louder. Not that I feel the Pass is deficient in the bass, just that the Bryston had more presence in that range. The power outputs are in the same ballpark, with the Pass nominally ahead of the Bryston. I don't often play my system loudly, so my observations pertain primarily to low to moderate volume levels.

I have only listened to Mark Levinson and Krell gear in stores, with a decent 20-30 minutes to listen to each, without A/B capability. Quick impressions I had are that Levinsons sounded quite neutral and slightly laid back, while Krells sounded more colorful, dynamic, with a more distinctive bass range. A jaded critic (not I) might describe them as boring and fatiguing, respectively, although the differences were actually quite minor, and one has to exaggerate to reach these characterizations.

Whether you upgrade depends on your economics and compulsiveness with respect to ignoring vs obsessing about small differences, sometimes differences that are not really as fully audible as seems to be reported by others. Of course the rest of your system makes a difference, although you should be able to hear amp differences with your Maggies. I think the cumulative benefit of small improvements can add up to a meaningful upgrade in sound, so I tend to obsess about small differences. Woe is me. Good luck.
Personally, my experience with the Brystons is that ALL of the amp lines you mentioned, for the most part, make better overall amps, sonically, than the Bryston. I don't think those Brystons are that refined really. The Pass Aleph and X series are another level of refinement over the likes of ANY Bryston amp really. Even some Krell amps, and Levinson amps would preduce better results.
Good luck
The Bryston 7B ST is an amazing amp for the price. The others are much higher in price and not necessarily better. There is a sense of quiteness about the Bryston and it has a vibrancy that reminds you to stop typing away on your computer and listen to the music!

Back in 95, I did an A/B comparison with Krell KRC, Mark Levinson No 38 and Bryston BP 25 preamaps and guess who won? The Bryston preamp was the most neutral and had the most transparant midrange at a much lower price.