I personally prefer Epic Sax. The fact that he gets a random buff for each 10 combo hits comes in clutch way too often, which makes him more forgiving to play.
And none of them are good defenders. If anything, HP's the only thing these 2 variants have going for them, but that's all Big Bands. But if I had to choose, I'd still go with ES
Agree with Tom in assessment for both offense and defense here. One more consideration might be if you’re thinking of upgrading to diamond in the future. There are lots of very good dark fighters to prioritize over megasonic, and not that many light fighters competing with epic sax.