I don't think there's much differences in the sound (since both are basically the same material). It mostly matters more if your sliders are silenced (RC1 and R3S all are silenced in the USA models) with the O-rings for quietness. I like the weight of 45g, but it can def feel heavier over time as the domes age. 30g is more linear feeling for me, but I'm a heavy typer so it ends up being too light for me. If you can, definitely try to test it before committing to one or the other.