I actually went from an unlocked iPhone on Tmobile to a Samsung Vibrant this last week. There are some things that I miss about the iPhone...I liked the calendar better, but then I found Gemini....LOVE IT. The other issue is contacts I don't like how that is all done....can't edit from the Vibrant! If there is another way please let me know.
Initially there was a battery issue...but that could have been NTS (new toy syndrome for which the only cure is to play with it). Today was much better, but I have also found a few tricks to help with extending my battery life(here on the forum).
Would I go back to an iPhone, possibly if Tmobile carried it(familiarity). Having to use outdated OS kinda of sucks, when you update your apps they won't work with the older OS. I have also had a Windows phone(MDA would have NEVER let that one go, but it flat out DIED after about 4 years!), and a BB Pearl (that was Ok). The MDA was the best and the Vibrant is closing in it quickly, and at the rate it is going knock the MDA out soon!
I am keeping my unlocked iPhone there are games and apps on it that are not available yet, and with text plus I can still text message with a wifi connection, along with email, ect. I also have several movies and books on there, for when there are kids that need to be distracted in the office.
I really like how the apps are separate, some you use all the time, some never and you can hide them away. The screen even in the lowest setting is AWESOME, yes it is worth yelling at you about. My son loves his, and he really likes that he can start homework projects on google docs, get a rough draft, and finalize on his laptop. Along with tuning his guitar.
Really enjoying the Vibrant!