I, personally, own a Yamaha (I like it...just my opinion) but I'm lookin' in to buying a Dynasty mello. I like the Dynasty range, though sound tends to be a little brighter than Yamaha, which doesn't have the range...if that makes sense...
Never personally tried the King, but from what I've heard of corps playing them, they seem a little TOO bright to me (though it may have just been the corps playing method...)