In my opinion, the English are underrated as well. In Civ I & II I liked to play as the English (because the island start on Earth map offers great protection & I'm a Canadian that's proud of his English roots). Again, the expansionist advantage gives you a leg up early on in the game with exploring/map-making and grabbing those goodie huts quicker. Plus the scout is fast enough to go around and barbarians you meet. The joy of the Commerical advantage doesn't really come into play until your cities get bigger, the extra gold really helps out, and you can afford faster research. I never really noticed how much this helped until I played my next game as Germans and constantly had to adjust the science rate to keep up all my buildings/army. If the Commercial Civs get big you simply can't match their ability to research fast AND maintain a large army. Finally, the Man-o-War may seem useless but can be a BIG leg up (bombardment and sea control) if you make a bee line for the techs.
Canuck