Muscovy are delicious. If they were dry, they were probably overcooked. I processed my first drake at about 5 months old and the others about 2 months later. None were dry or tasteless. I plucked my first, by hand, what a nightmare. I skinned the others, very quick, you lose the fat but my hubby has cholesterol problems so no biggie.
I cooked the breast like I would a thick filet. Season with salt and pepper, sear on both sides then into the oven to finish. I think (its been a while) I did 400 degrees for maybe 20 minutes. You don't want a well done breast and I usually ended up somewhere between med-rare and medium. The breast meat was huge, never weighed but probably 1-1.5 lbs per breast.
I'm waiting for my birds to reproduce so I can put some in the freezer! I do have a hen that decided to start setting at the beginning of the month so December ducklings for me.