I heard these speakers on an Atoll amp and really loved them. Any other recommended amp to match them with? Also heard them on a NAD 325 and a cambridge 640 but the result was terrible.

Also, any feedback on their performance when listening at low volume?

I use them with a Rogue Cronus, and am pretty psyched.
Which Atoll amp? How about getting an Atoll?
If you don´t like to spend a lot of money try Rotel, you gonna be surprised, a more expensive scenario try Classe, if not go to the Tubes, VAC is my choice, anyway if the speakers are new try to put some miles on it first.
I heard the Cm7's with a Rotel 1552b AMP and It was phenomenal. The dealer had a sub connected to it, But even with it off the sound was bright, but it had deep bass as well.
I've got a pair of CM7's. They are good speakers but I've found that setup can make them sound far better.

I mounted mine on Mapleshade Platforms with brass footers. I tilted the speakers back by using a custom made brass spacer under the front footers which puts all drivers at equal distance using a laser measuring device from my head, then the platform was coupled to the floor with another set of brass footers. This immediately brought them to life and tremendously improved the imaging and depth. The tweeter ended up being slightly above ear level using the platform and footers, with drivers in perfect time alignment with my ears. This setup was stunning.

They really need room to breathe and I've got mine 6' from the wall behind, about 1/3 into the room which is wide so side reflections are not an issue. I use quite a bit of toe-in, and from the tweeters, the lines extending directly ahead would cross slightly ahead of my nose from my listening chair. This produces a holographic image extending well beyond the speakers with plenty of depth and air between instruments.

I'm using modestly priced equipment, NAD M3 Amp, Cambridge 840c CD Player, Bryston BDA-1 DAC, and bi-wired Discovery Essential and Essence Cables, and getting sound that rivals some speakers costing $10K in my room.

They are sounding far better than their price would suggest but require careful placement not usually used in speakers in this price range. A little effort goes a long way into getting good sound from these underrated speakers. My Dealer heard them in my Home and was amazed at the sound I'm getting, far better than he did in his showroom.
I used to have them and could not get them setup correctly in my room. Way too much bass resonating off the floor. After several different spikes and Herbie's devices I ended up placing them on Aurelex Gramma's. that took care of a lot of the problem.

I ended up selling them because rear ported speakers don't work in my room. I even tore the Drywall off the entire wall behind the speakers, packed it with insulation and put up new drywall. That was one of the best decisions I ever made but still opted for front ported speakers. I didn't like the plugs all the way in the ports and didn't like them all the way out. Not a bad speaker if you can pull them far away from the wall.
I found these speakers need air to breathe if you want to get the best sound. When I see them setup in dealer showrooms they always have them fairly close to the rear wall with no tow-in and sound mediocre at best. Mine are about 5.5' from the rear wall and toed in so that the tweeter's cross slightly in front of my face. The sound is wide and spacious with excellent imaging, depth and air around individual instruments. They sound far better than their price range would suggest. Placing them on solid maple stands anchored into the subfloor makes the biggest improvement from the stock spikes or stands.