We had some Pekins this year, sourced from Central Scotland Smallholders Association via Cherry Valley.
They were your typical big white duck, and the meat was very tasty and not at all fatty (tasted somewhere between chicken and lamb actually!). I found them a lot more hassle to rear and prepare than chickens, and I'd say not as much useful meat on them either.
So, not something I'd do again in a hurry, though worth trying once for the experiment.
HTH!