I bought Nidalee right before she was reworked. What I got was an awesome Mid laner I loved. And then Riot butchered (or so I heard) one of my favorite champs. I just can't bring my self to play Nidalee top because I remember playing her mid. So explain to me why they changed her so much? What was wrong? And why do people consider her a bad mid in the first place? To me she is still good.
Her play pattern was poor and uninteractive since she wanted to stay back and just land spears, while healing. and no reward or reason to go in and use her cougar form aggressively, so was mostly used as an escape.
AP on her isn't bad now it's just different (though I really recommend 
on her even for mid AP), she's stronger top lane mostly due to how she's able to make use of her passive from the bushes and benefits from the longer lanes for pouncing. She's still alright to play mid and AP, I've seen plenty of people do it successful, it's just she's more fit for top really is all.
I think she needs a couple love taps. Her power level is about right, I think. However, Nid's primary mehanic is getting targets hunted, but her ability to get the hunt debuff onto the target she wants is really inconsistent.
A while back I saw someone suggest a change that I think would go a long way:
Minions can no longer trigger traps
