I spent most of my listening time this past long weekend with the Rega 2s and modified Mission 710s (upgraded 770 woofers). The experiment of replacing the cheap car stereo woofers with ones from a higher Mission model worked better than I had hoped. The litmus test is the midrange, and this speaker does it right.
Comparing the two is an exercise in hairsplitting. They are both excellent. The Regas have an edge in the imaging department, due, I think, to their narrow baffles. The Missions are slightly more solid in the bass. I could live happily with either of these speakers for a long time.