Both Harbeth 30.2 and JA Pulsars are excellent speakers but they’re not going for the same buyer profile IMO. 30.2 is more of a monitor speaker and has a distinct sound. I would never advise anyone to buy the 30.2 without listening. You will either hate it or fall in love with it.
Pulsars are more traditional in the sense that they will sound more similar, but overall much better, than your existing speakers.
Having said that, given your room size why are you looking at bookshelves? You can easily accommodate floorstanders in that room.