Yeah this is pretty much why so many people have this sentiment that Daigo's Evil Ryu sucks or isn't as good as his Ryu. Their is so little footage of his Evil Ryu and what little footage we do have isn't impressing many people who are use to seeing how Sako played Evil Ryu.
What we have seen is him losing to Tinshi and looking less than stellar in a team tournament. Then we have him looking really fucking solid in the USF4 console launch stream and in those Japan tournament matches against Mago, Jihuta(Gouken players), and Gachikun. And many people who saw those matches were left unimpressed because they felt he played very boring and didn't utilize Evil Ryu's mix ups.
We haven't actually seen him in long sets or in a American style tournament yet. EVO 2014 will be the first American tournament we see his Evil Ryu in. Anything less than top 8 will be pretty disappointing and let the doubters feel justified in their previous claims. I think he'll do fine though, I'll be rooting for him to take it all.