I'll have to give them a shot, but admittedly the nostalgia is almost certainly a big reason I love the RA OST (and starcraft as well).

I didn't play enough doom to really love it in the same way.

Right, it's less about the nostalgia, and more about the tempo that I find really enjoying.

Man the Terran tracks are so incredible

It's the same backend, so it's a bit like a fun theme difference. I played Dune2 first, and like RA too.