iPhone 4 wifi speed?

Just wondering if iPhone 4S is "more powerful" or has better wifi than the iPhone 4.

I have 4 and my wife has 4S. Using Speedtest.net app on both she regularly hits 34mbps download and 10mbps upload on the 4S whereas I usually get 14-18mbps download and 8-9mbps upload on my 4. Can't understand why. We are on plan giving us 40mbps download and 10 mbps upload.

AppleCare have said they should be similar speeds as both have the same wifi chip. Called local Apple store but couldn't speak to Genius. Whoever I spoke to said speeds should be similar on both and a Genius Bar appointment may be an idea.

Anyone else noticed something similar? Apple store is a fair distance and don't want to travel down to be told nothing is wrong.

Appreciate any advise.

The 4S has a faster processor, so it can "digest" downloads faster.

Just had BT Infinity installed.

62.3mb download 11mb up on MacBook

Getting 32-40mb up and 10-11mb up on iphone4S

I have a 120mbs connection from virgin media uk

Superhub1 - 2.4Ghz

iPhone 4 16gb 6.1.3, speedtest.net app shows 20Mbs

iPod 4th gen 8gb 6.1.2, speedtest.net app shows 24Mbs

iPhone is full, iPod is empty