optimus 3d has roms of 2.3 gb..check xda forums.
i personally did not like the plasticy feel of s2..
would rather prefer the iphone 4s..
also,the optimus 3d is kinda big with the 4.3 inch scren.However,the build quality is very good(rubberized back like optimus 2x).
or if win7 is not a prob...