I have yet to see person who says that classics don't have flaws. Though I have already seen more than one person who defend DmC to the death while refusing to admit a single flaw in it.
That's a bit hyperbolic, to be honest. You're either saying that for the sake of argument, or you haven't been paying attention to what people who like DmC say (which wouldn't really be surprising). Certain "flaws" are extremely subjective. People like to say DmC is a sh!t game because it doesn't meet the expectations they unjustly wanted it to meet.
But fine, you want my criticism of the game?
! - Despite the potential the game's system has, I'm disappointed that they didn't have more abilities. There's a lot of inputs that went unused that would have been perfect for things like Twosome Time, Gunstinger, and a couple other moves. Plus, they totally could have brought back my favorite moves from DMC3; Wild Stomp and Free Ride.
@ - As much as I love the art style in the game, some of the effects I feel lack the mystical nature of some of Dante's moves. I loved the magical inclinations with Kat, and would have loved to see more on Dante, too. I miss Air Hiking from a magically created platform.
# - I couldn't give two sh!ts about framerate, but I would have liked it to be faster, just because I
like fast-paced games. The 20% Turbo that SamD shows off is exactly what I wish I had on console.
$ - There's a few things that I wish they would have fleshed out better, but then again I'm also a huge fan of Metal Gear Solid and Final Fantasy, so my desire for a lot of things divulged through cutscenes might be slightly skewed
% - I miss the File system, it was a great way to get some more insight on smaller details.
^ - I hate that once again, my favorite firearms become slightly less useful later in the game. It's like clockwork, almost. Gunslingers are destined for obsolescence it would seem.
& - While I like the design of Dante's Devil Trigger, I don't quite like that it's
not a power amp like in the classics. Because of how powerful it is, I also don't particularly like how long it takes to build up, and how quickly it depletes. And I don't like the way the meter looks for it, I would have loved some kind of spraypainted glyph design or something.
* - Some of the sound effects used, while realistic, don't provide a great accompaniment to the crazy action you do.
( - I miss taunts. I'm glad while getting rid of them they modified the Style meter's retention behavior, but I miss the taunts because they were just a fun thing to do, and they generated magic. I could understand not wanting narrative-breaking taunts, but when they had scripted lines for the characters to say anyway, an easy system could have been made for creating a specific set of taunts to perform within the context of certain fights.
That's my criticism of DmC. However, these are not exactly flaws, because a flaw is something bad or wrong that is a detriment to the product, like a faulty fuel injection system that causes an engine to blow up. As a game DmC is perfectly fine. The only flaw that I can see that's truly objective is not explaining the rules of Limbo better, because it works against helping the audience understand interaction with such an abstract dimension.
-the way he hides can be often strange since he tries hard to not let Mundus see him, yet he walks outside with Dante and Kat a few times and shows himself during the trade.
To be fair, they didn't know what Vergil looked like until the Trade, and didn't even know his name until Kat told Mundus under torture (just before the trade). Pretty hard to find a guy when you have no idea what he looks like or who he is; Vergil just walkin' around in town is just another trilby-wearing douchecanoe. It'd be like me trying to find you, when I don't know your real name or what you look like