I own a pair of Martin Logan monoliths and had the same problem. I'm integrating a sub for movies only, but most of my testing was using the processor in stereo mode with the sub with music to see if it could seamlessly integrate with the logans. I wound up with a Genesis servo 12, which I doubt is as good as the 928. I did not listen to the REL products, but probably would have if I had not liked the servo 12 so much. I'm glad to see there are no velodyne recommendations--I tried them and they just didn't work at all with the MLs.
Looking at a new sub for ML
I have ML Aerius I, with bak vk200 amp and nht 2swpi sub; believe it or not the nht 2swpi was better than the sunfire, velodyne, paradigm; when it came to music; not trying to insult any of these subs/sub owners, but for the money nht was better. The system sounds great but I would like to upgrade my sub. Thinking of the REL storm III, Genesis 928 or something in the $2000 range new or used. I do use the system for HT, but when it comes down to it music is my love. Now can the 928 intergrate(accurately, detailed base) into the system(w/ML aerius i) better than the rel storm III. I've never listened to the 928. And the rel I did hear was not setup properly. Help. Thanx