I recently turned in my old Rumor for a Rant because of some shut off issues on the Rumor. I have been pleasantly surprised at the Rant since I got it. The Battery Life is amazing as long as you don't use the email features where it is constantly checking your email for you. The Screen is very readable and has a very strong picture.
I love the fact that the Phone is 3g which means that it downloads and browses the Web very fast, Even with the new 4g technology coming out soon I will stick with this phone for awhile now. It's not a smart phone by any means but it does have tons of features. I love the Carousel feature where ou can keep your most used things in a bar at the bottom of the screen. So far I keep track of all the news sites, NFL, AIM, YahooIM and MSNIM. It can also keep track of local movie theaters for me playing times and ticket prices.
So far I have only had one issue with it when I first got it and that was a lock up problem that was fixed in an update the day after I bought the phone. So since then I have had no isses with it. As for the Durability so far I have found it to be a pretty tough phone I have dropped it a few times now and it still works perfectly.
The strongest feature on this phone though is the Texting with it's full sized QWERTY keyboard you can make people think you are a texting god.