I haven't played Vi so I can't talk about playing her but here is what I do know from experience with fighting with/against her.
A) I don't know whether its cause I'm playing Master Yi or if the other people suck but I find Vi to be absolute trash to kill. I don't know. Judging from what other people are saying, it probably is the person playing as her that sucks. But it's like a joke to play against her. I find more fun killing Garen or Cho'Gath.
B) I haven't played Vi, nor do I plan on it (it's a hell lotta IP to get her and I'm not paying for RP) so I cannot state anything about how she feels.
C) I've played with her (a team mate chooses her) and she's pretty mobile, pretty strong after a couple levels. I definitely recommend partnering up with one if the person playing Vi is decent.

Double post. My bad.

VI is awesome, the role she gets is exactly my kind of game. Rush, break down armor, disable carries. I love her mobility. Her weaknesses are well located.... rushing in to soon is deadly, failing the Q gives a great advantage your target to counter you, spending E to soon makes your damage output weaker.

I like to play her a lot, is awesome. What I like is combining her skills.

When facing her, is really funny to me, because I know her a lot so exiting be careful about her skills.

the only thing that i don't like is her 3d model, because it has some differences with the splash art.

I mean, the splash art is reallly awesome, but when you see her face in the 3d Model, is a lot different from the art, is like she is more old and she don't have the same spirit that she has in the art.

So, the face is very different, and there two other difference, but they're not so important, like her goggles are gold, and her knuckles red.

but I like her a lot, and i feel very useful during the teamfights.

I have only played on Vi's skin, but I am assuming the same thing applies on her normal skin as well. Her taunt has no audio file with it, or at least I haven't been hearing it. I do think it is awesome that she flips her sunglasses either up or down with her taunt, but I do wish there was some audio with it. Other than that she is really fun, I have been jungling her a lot since she came out. I do wish she had more CC but I understand that she is well balanced with the small amounts she has.

While others may complain about viability, I feel like the design team have done a GREAT job with both Zed and Vi. Easily two of the most fun champs to play.

she is op

Gypsylord, why is there so little counterplay to her ultimate?

i just went and jungled with her and grabbing W first now makes it so you have no pots and half hp at lvl 4 which im guessing was the idea. now most Vis have to grab E for maybe a faster clear