For me, the main disappointment with the 4s is the small screen. But in May, I sold my 4. Presently, I'm using my 4 1/2 year old original iPhone (bought on 6/30/07). So, upgrading to the 4s, even with the same small screen, is a no-brainer.
Recently, I have tried out a couple of android phones and a tablet. Android is fine, but it doesn't integrate as well as iOS does with my other Apple products.
Specs, by themselves, are not that important. It's how well, in real use, they perform. The new 4s appears to be considerably faster. Also, the camera looks like a good upgrade. Too, I'm curious just how well Siri works in real world settings. Yes, on paper, some new Android phones look superior to the 4s, but in actual use, I'm not so sure.
If you want to, because you're not happy with Apple's 4s, get an android phone, just keep in mind how it will fit with your other tech.