Quick one: aside from a marginal weight difference, and a few hundred £/$, is there any meaningful difference between chorus and record (assuming both mechanical, not EPS, and both disc)?
Not really. Chorus has always functioned as well as Record and Super Record. You get a few more bits of carbon and maybe titanium on the higher end groups. Super Record comes with really nice CULT ceramic bearings but lower groups can be upgraded to those bearings later for not too much.