Heh, speak of the devil. I just today received a pair of Soli P cans on loan from a very generous member here. These have been around the block for awhile, so are fully broken in. As I learned at CanJam, they are more efficient than Susvara, but they still like power, so I'm running directly off my NAD M22 V2 (on lowest gain). After a few hours of listening to various genres, my early impressions are that these are great for rock and classical/symphonic (if you like a more "romantic" sound). They clearly have a more prominent low end than the Susvara, but it's also a bit slower, woolier, and less pitch-specific. Imaging on these is like the lens is slightly out of focus. I'll have more to report in a day or two, but I will say these are a very enjoyable listen overall.
The one thing that I find quite annoying is the amount of squeaking and creaking that the pads do with even minor head movements. Are these pads simply worn out, or does anyone else have the same issue? The pad and headband material is also a bit irritating to my skin after wearing the headphones for a good while. Comfort is definitely not on the level of the Susvara, unfortunately.