ok gee, i don't know if i can vote on this yet, the portuguese get their ship a lot sooner, and with 2 scouts on a carrack they can find the best settling sites and send a galley with a settler and a unit in tow, no biggy? especially being imperialistic, will have the new world settled in no time (maybe a good use for colonies?). So will deffinately win the race for copper, iron or horses if needed. This can be a good advantage. And yes the UB is very useful for supporting the economy after expansion, that expansive trait will boost that aswell.
the dutch seem to have more of an aggressive looking form of expansion, with 4 cargo spots and unlikely to be sunk if you dont hang around for frigates and alike, this deffinately could put a few portuguese settlements at risk. And with the bonus water production later in the game, they will be able to build their modern ships faster than anyone else, destined to rule the seas twice in a game.
Are you a warmonger or a builder i guess? *votes portuguese*
Edit: oh but technically, ruling the seas twice? do i have to vote for the dutch?... I'll vote equal