Diana has got to be the most overrated champion I've seen.
Moving along, if you're referring to Dominion, we don't get any champion balance. As for SR, their concept of balance revolves around what's being played in a tournament or whatever random thing they decide to nerf that patch (it might be right, it might random, or on occasion it's something they should have done months ago, coughrivenult). As for Dominion, item balance has gone out the window since Torch. Ohey, Zhonya's Ring is back. They did what to DFG? They're doing what to penetration? /duck under table
People don't notice the items as much because, one, they're giving some underpowered picks face time and two, everything was eclipsed by Black Cleaver. Nobody notices Zhonya's Ring because Torch and penetration spam is covering for it, especially considering the best (or even just good) picks benefit more from pen spam than Wooglet's first. It's like ignoring how dumb some of the top shelf picks are just because Kassadin is running around and ruining people's matches.
Anyway, back to Eve: I play AD so this has absolutely no impact on how I play. The damage on the ult was nice, but I still get most of it unless they've been poked down or I'm cleaning up, and in both of those cases the shield is more important for diving in a fight and slaughtering everyone. I feel bad for AP Eve players (bit much imo) but the irony is delicious considering people think AD is worthless or something just because it took months for people to discover that DFG was bat**** OP on everyone, and then on burst assassins, and now it's silly again.