I don't really use the browser, I've found it's UI too cumbersome.
I only use my Kindle for reading- that of which I absolutely love it. I chose it over other e-Book readers specifically because of it's battery life and e-Ink technology. The bonus of the non-subscription based 3g access to my Amazon account was also a deal maker. Being able to download new books without requiring access to a WiFi network is very convenient.