I've noticed the iPhone has less contrast than my touch had. I would prefer a screen with a bit less contrast than too much (which my touch had). You can alway crush blacks, but it doesn't look very good to "un-crush" them.
Also, I can confirm that the iPhone does start to feel warm a bit faster than my touch. (esecially towards the top) And yes, the wifi is slightly better range on the touch. I was trying to connect to my neighbor's connection, with my touch I could go about 5 feet further from their house than on my iPhone.
In the end though, 3rd party applications, calendar, mail, etc. are much more valuable to me than having to go 5 feet closer to a hotspot and having to deal with a couple degrees of extra heat in my hand.