I've had my iPad with Retina upgraded for a few hours now and it's definitely going to take some getting used to.
So far, my favorite thing is the quick access to the Control Center.
The way the Photos app groups your photos is strange but not intolerable.
The clock app shows the current time now, which is very nice.
If using a passcode I find it much easier to type in your code correctly since there are big numerical buttons instead of the smaller squares.
As far as the battery life, I can't speak to that yet but will be interesting to monitor that to see exactly what happens.
Some things I don't care for:
1. The pre-loaded icons are pretty but don't mesh well with the "old" look of my other icons such as Twitter and Facebook. Makes my homepage look a bit more messy and less uniform than I prefer.
2. Don't care for the way the icons "wiggle" or "float" when holding the iPad. While rocking in my rocker-recliner the icons rock with me. Very weird and distracting to me.
3. Don't care for the bright white color on the Contacts, Notes, Reminders and Calendar apps when open. Will be very eye-straining I fear. I tried dimming the overall brightness and that helped a tad but still not great.
4. Don't care for the small, thin font used for the icons and the white color makes it very hard to read, depending on your background photo.
So all in all, nothing spectacular but nothing I absolutely hate. I'll get used to it and will be completely fine with the changes in a few weeks.
