well i upgraded this month and got the experia X10, fantastic phone, there is nothing it can't do!....Apart from it's battery last longer than 3 hours!!
The phone is like i said, brilliant, easy to use and some great apps in the android market. When i took it back the sales bloke said it would take 14 days for the battery to bed in properly...Just so happens that your 'returns' period on contract is 14 days!
So i changed it for a blackberry storm 2. And i have to say i love it
The wacky push button screen is a little wierd to get used to, but after a day or so you will be using it like lightning.
I will admit, there are not as many apps on the blackberry as the X10 and not as many features in generall but its still a fantastic phone, easy to use and more stylish than the X10 i think
I don't know about the other 2 though, sorry.