So far, it is ok.
The build quality is solid. The rubberized back is nice to the touch and will not scratch easily. It is nice to have actual buttons for Call, End, and Back, and they work every time. The size is ideal for holding up against my face during a call. The sound quality is the loudest of all my previous phones, I find myself turning the volume down at times. The screen size is big and I can see it in direct sunlight. It is nice to have an open USB port, and the buttons on the side are placed intelligently. It won't accidently slide open and takes a little effort to open it and close it, which is ideal. The touchscreen is as responsive as I would expect. Every time you have to scroll anywhere, you must touch some type of existing icon or button, and it might accidently activate the button. I haven't figured out a good mix of touch pressure and scroll speed, so I end up moving my icons and opening up programs, but it is easy enough to press the Back or End button to get out of it.
I have cutomized every aspect of the phone. As everyone says, you can not use your own wallpaper on the two customizable screens. You can use the eleven pre-loaded images for the custom screens, and you can NOT copy an other images into this directory. You can choose between eight clocks, and six fonts. There are three menu color screens of which is what determines the background color, the text color cannot be changed. You can change the touch feedback vibration and intensity, which I turned off to save my battery. You cannot change a lot of settings, like to limit the use of internet, there are more that I am not thinking of right now. You cannot lock the icons on the customizable screens, but you can make they align in a grid spacing or allow them to float anywhere. The custom favorites screen is cool, but you should have a face picture to go along with the contact, otherwise it is a generic icon with no way of seeing whose contact it is. There are four permanent icons for dial/contacts/inbox/ and menu. Very useful.
Every time you press the menu button, it defaults to the ATT branded screen, the second screen is more ATT/Social networking apps, and the third screen is the phone basics, which is the only screen that I will ever use. The contact screen is nice because you can easily scroll by the letters on the right of the screen. To shorten this up some, I bought the phone because of its alarm clock and calendar abilities. I have added nine alarms and it seems to be able to add more. The alarms are 100% customizable in every way and is are the calendar. To add to why I like this phone is that you do not need to have the phone turned on and the alarm will go off on schedule and the alarms are repeat on the schedule.