I just bought a pair of the RB-75s. I uopgraded from KG 2.5s. I, too listened to the RB 35s, especially since they were roughly 1/2 the price of the 75s, but thought the 75s sounded a bit better and I did not want to settle for the 35s since the reviews I read on the 75s were great.
I put them on Omnimounts with great effort so the cabinets will not come apart since they are not designed to be placed on anything by flat stands.
Get them, you will nto regret it.