i switched from iphones after 4yrs to the Galaxy Nexus in December(just switched back to iphone in march)...
The speeds on 4g LTE were twice as fast as my home comcast..On average with LTE I was getting speeds of 35-40mb down and 12-15mb up
It was just crazy fast....BUT, there is not a huge difference at all while web browsing. Maybe 25-35% faster at times? But for the most part i visit mobile sites and prefer them over the real sites on my iphone. With mobile sites there is very little difference in loading times.
Streaming video and music there is an obvious advantage.