I think ditching Google Maps was a bad idea in the first place. Google has it right, so why change it? I'm sure it has something to do with money somehow though. I haven't tried Apple's map app, and I do not intend to. I will keep iOS 5.1.1 for as long as possible.
For me it needs a lot of work ! There are not enough details like the previous Google maps,and it looks so messy in some locations !
So I think this is a big disappoint. Hope they make it better in the near future.