My girlfriend and I use a T-cross with different saddles, all of which penetrating types, but with more or less additional support for the buttocks. We are both sadomasochists, but with different tolerance levels for certain types of pain. The T-cross, which we can separate with a power drill (metal connection plates on rear), if needed, serves the purpose of lingering or lasting best, so we chose to leave each other hang for some while and/or make each other come.
I also experienced the T cross with friends from Spain, which also preferred this type of concept incl. saddles (wedges aka. "Spanish Horse"), so feet did not require support and can be attached with ropes, leather shackles or metal chains. That adds most effect to kinky crux play, I believe.