This is going to be one of those things that polarises people. One half will love it, the other will never use an iPhone again, lol.
I personally think the design ideas are great and it's the first time the actual functional side of the design has been properly overhauled in years. The aesthetic side definitely needs some work, I'm not sure why they feel the need to put such garish colours in at times. I know it's to make a statement, but it just doesn't look that great. Mainly it's the app icons I'm talking about, some of them like the Safari one look legitimately amateur.