Though I have no personal experience with a two shank machine, I do hear trash clearance/flow can be an issue. Many have good luck with seeding between last years rows, but that might be challenging in pothole country.
JD 1870 is also a twin shank, with a fairly good reputation I believe.
We are full liquid fertilizer blend, so we don't like the idea of MRBs either, due to P getting too far from seeds. Our last 2 drills have had paired rows and we like it, but don't mind a bit of disturbance either. Maybe a sideband boot would work for you as well..
As far as the seed twins, I do like the idea of the SM canola tank. When we were looking for our new drill, we considered them the top of the 2 shank machines. But again, no in field experience