I just bought Dragon Spirit from Rover so I look forward to playing it again on the HuCARD format. Haven't played Dragon Spirit on the Turbo since it was on demo at Radio Shack. lol. Anyway, I just went on MAME and played a couple levels of each, and I have to say that Saber wins out IMO. Just a general improvement overall (i.e. BGM, graphics). Nothing drastic, but, at least in the arcade version Dragon Saber added some minor scaling with the enemies (i.e. those creatures that rise up from under the lava in the beginning of stage 2 - does the Turbo version try to emulate that scaling at all?).
Anyway, this is about the TG and not the arcade, but if these are at all similar I think Saber wins out.
Also, to be fair to Dragon Spirit, the arcade wasn't the prettiest thing to look at either. lol. People are really hard on Dragon Spirit, but man the TG port does it quite well. It's funny, but the TG could've really improved upon the arcade version of Dragon Spirit.