I don't dislike Mask of the Sun quite as much as you do, but it is probably my least-favorite Ys title, so I can definitely relate.
Definitely give Dawn of Ys another shot, though, as that's actually one of my FAVORITE Ys titles. The differences between Dawn and Mask are night and day -- the dungeons in Dawn are exceptionally well-designed, the story and pacing is perfect, the graphics and music are some of the best ever encountered in the 16-bit era as far as I'm concerned, and the bump system is fun, rewarding and well-balanced. Hudson did an incredible job with the game, and really captured the spirit of Ys I & II while updating it to 1993 standards. It's a lovely, lovely game, and is absolutely an improvement on Mask of the Sun in every conceivable regard as far as I'm concerned.
-Tom
Yeah, Mask was one of the later Ys games I played and it just didn't compare in any way whatsoever to Dawn. I thought Mask cut out a lot of content from Dawn and just didn't have nearly as interesting boss fights or music.. it was a lot more forgettable too. Dawn is probably my favorite of the "classic" (pre 6) Ys games.