I'm up in the air over the Drac X and super castle. I thought both games were very well designed and very playable. I love the whip brandishing and swinging of super castle, and i love the back flip in Drac x. Both had great level design but I have to tip my hat to the SNES version unfortunately they were able to do things just not possible on the TG16 and I say this with the utmost love for my TG but the rotating rooms and swinging and skellies busing out of windows from the "tube room" in super castle blew me away.
I say: play the hell out of both games. I did, to point where I was sick of them (well, sick of all the old Castlevania games).
Let a few years elapse. A decade, say.
Ultimately, I find myself going back to PCE DRAG EXXX more frequently.
Believe me, I don't hate the SNES, or its Castlevanias (they dwell within a small crevice of my heart), but they simply can't compare to PCE DRAG EXXX.