Other posters have mentioned that they have difficulty parsing the sprites because of the sprites and how they overlap with the darker backgrounds. Steaks and Sloth have made some pretty good points and I'm inclined to agree with them, even though as a long time fighting game fan, I'm apparently accustomed to some of the problems (and Steaks even addressed that fact in a more recent post.)
It's a shame, but there wasn't much difference between the last few versions of the game and the retail version, so I guess it'll just be one of those little things about the game that people have to decide how they feel about it. And I'm not saying "just deal with it", so don't start up with that; I know this sort of thing affects the feel of the game, which can make or break a player's experience, so I think it's going to affect people in different ways. I dunno, maybe a soft-ban on dark stages would help with the palette issue, although it wouldn't make the animation any smoother.
Speaking of animation, there is one thing I just wanted to ask about Double. I was under the impression that Double was supposed to move abruptly and be hard to read; isn't that the point of her playstyle? I mean, as quick and bouncy as the animation is for characters in general, Double's animation is even more so. The almost-instant cross-up dash, the way some transformations are fast while others are slow and detailed (but also jerk wildly when canceled into other stuff) and other stuff like that made me think that she's just supposed to be hard to follow when used properly, like the handful of shapeshifting characters that are in other fighting games.
This doesn't really apply to the other characters, but I think that Double is a special case, and I think that it works for the character (although of course, whether or not a character that relies on being hard to read is a good choice from a gameplay design is always up for debate.) What do the rest of you all think?