My company gave me an iPhone 4S last Friday with service on our corporate Sprint plan. It will probably be going back to Sprint. The 3G speeds are so pathetic that I have left cellular data turned off and just use the WiFi side. I already have an iPod Touch 4 and have basically reduced the iPhone 4S to operating just like it. We will be probably be deciding on Monday if the devices are going back. At this moment, I have it totally powered off and in its Apple box so as not to risk damaging it if we do return it. If you really want an iPhone 4S, I strongly recommend looking at the other two carriers though I myself will not deal with AT&T. Unlimited data is great but with the speeds Sprint is getting, you would be lucky to use 200MB in a month.
I support the right to keep and arm bears.