Rom all of them
Verizon Equipment Guide Says DROID Bionic Will Launch in All Channels September 8 - Droid Life: A Droid Community BlogDroid X2 is 5.02" x 2.58" x 0.39" according to Motorola's website (after a conversion). So it appears you are right, they are basically the same size. I really wonder on the thickness though. We'll see.