I upgraded my 4 and iPad 3 last night too. It makes the 4 feel a little faster, but it is kind of crashy on it: when I tried to move some icons around, it reset my phone. This happened twice in a row, and while my phone was talking to iTunes. Some other built-in apps seem to be unstable as well. The iPad 3 works great, as does Siri, though I'm not sure I'll be using it much, especially on the iPad. Turn-by-turn is only on the iPad, but it seems a little silly on the iPad as well.
Maps is not quite the disaster people make it out to, but it is very clear that Apple is years behind Google, and will probably remain there forever unless Google gets out of the map business. I hope Google puts out their Maps app soon. Public transit directions are gone, and that was a godsend in an unfamiliar city, and it worked very well. The 3D interface for the map is surprisingly intuitive with the touch interface, much more so than using a mouse in a 3D CAD program on a PC, for example.
Maps could be a pretty heavy monkey on Apple's back for a long, long time. It is unbelievable the resources that Google puts into maps: there is a lot of high-caliber brainpower working on Maps in Google in addition to the brute-force mechanical Turk stuff described below. And all their data is produced internally, whereas Apple licenses it from outside companies like TomTom.
The Atlantic had an article on Google Maps that illustrates how much effort Google is putting into Maps:
The sheer amount of human effort that goes into Google's maps is just mind-boggling. Every road that you see slightly askew in the top image has been hand-massaged by a human. The most telling moment for me came when we looked at couple of the several thousand user reports of problems with Google Maps that come in every day. The Geo team tries to address the majority of fixable problems within minutes. One complaint reported that Google did not show a new roundabout that had been built in a rural part of the country. The satellite imagery did not show the change, but a Street View car had recently driven down the street and its tracks showed the new road perfectly.
I like the little refinements, like new tabs in iPad Safari finally (finally!) not placing the input on the search box. I'm glad there's a clock app for the iPad that you can set alarms in.