Seems like its the new iOS 5 software, not the hardware, that's giving the boost, according to PC Magazine's Alex Colon:
Compared to the latest and greatest Android devices, the iPhone 4S is still tops for Web browsing. It scored significantly better than the Motorola Droid Bionic on Verizon, the Motorola Photon on Sprint, and the Samsung Galaxy S II on AT&T. But again, these benchmarks aren't completely what they seem.
-PCMag.com, October 14, 2011