I have a Samsung Galaxy. With AT&T.
Had a Razor prior...wow. It was like going from a horse carriage to a Cadillac (to me). Can't tell you the pros or cons of each type though. Went with Samsung mostly because it is compatible with Windows and I'm in real estate and most of the applications are not Mac / Apple compatible.
Good Luck..
My step-father is also in real estate, and he too is a Windows user. He started his Smartphone walk with a Samsung Galaxy... and absolutely hated it. He loves is iPhone 4. He hasn’t run into anything that it prevents him from doing - and being a Windows user doesn’t have any impact on using an iPhone.