I used Oly stuff when it was new, as companions to my Leicas, and there was one thing that always irritated me: the lack of anything to hold on to on the right hand's side. It's really small over there, compared to every other camera, and I always had a problem with that. Somewhere along the line I picked up an OM2n-SP, and in addition to being a really wonderful camera, it had an accessory lump grip you could screw on that side, the smaller version of what all modern cameras have, that really was a help in holding the d!@#ed camera. If the straight OM2n had that, that would decide things for me. Otherwise, if I were looking now, I'd find an SP with the grip. It really makes a difference. After that camera, I bought a winder for my remaining OM1 just to have the grip.
I know the SP has collected a lot of demerits for internal complexity, though.