Pierce wasn't so much playing Bond as he was playing Remington Steele playing bond. Increasing amounts of aerosol cheese permeated his lines to such an extent that one would have to be David Caruso to make more a mockery of their delivery. If Moore is a poor man's Connery, Brosnan is a poor man's Moore.
That said, Die Another Day was handled so miserably, that it would be wholly unfair to lay the blame of that human atrocity at his feet. Forget waterboarding, showing gitmo prisoners this movie would be the most serious breech of the Geneva Convention.
His was tense and wary, appropriate for a man in his line of work; so much so that all other Bonds seem cavalier and lackadaisical by comparison. His was also the consummate professional, his primary goal was to the mission, not to the next girl he could get into bed; mishes before bitches or something...