I've seen some pictures of Alan Shaw standing next to the new SHL5s and they look much smaller than they used to. Either a) they've manage to fit the 3 drivers into a tiny cabinet, or b) Alan Shaw has expanded enormously, of c) all Harbeths look very compact since I got ESL63s.
The only difference in 'Radial 2' appears to be the surrounds, which were introduced for the C7ES3. So it's basically a crossover rethink with AS's beloved new modelling software, but not much change elsewhere.