Djack, although the mussel inspection issues and other restrictions here in Colorado have rendered motorized duck boats nearly useless, I still enjoy the times I take out my DP. I heartily agree with Rob that it is not sized or designed for traversing big open water. It's plenty stable when laying out in a chop when the decoys are in the water, but with a full load I hedge on the side of caution.
In addition to the type of water and distance you need to travel, what you plan to carry will be a factor in your motor choice. If you're not toting a dog and a mess of decoys, you can get by with a heavier motor. After deciding that I wanted a lower profile and less weight, I decided against a mud motor. After playing with various trolling motor/battery combinations, I settled on an old short-shaft 2HP Evinrude outboard with an internal gas tank that weighs in at a mere 25 lbs. I see Momarsh currently lists the DP capacity at 550 lbs vs. the 425# Coast Guard rating on mine, so maybe they've increased the flotation.
I do have a camo deck cover with cable-tied Invisigrass, but...again due to the boat inspections...I can't leave it on the boat. I've repainted my boat and one set of door covers to work in shallow open water and on reservoir sandbars. I use the grassed deck cover and a second set of door covers for marshes and rivers, and stuff them in a compression bag for transport.
Rob, I can't tell for sure but it looks like they've replaced the quick-tight/cam buckles where the door covers attach to the deck cover with some other type of device. If so, that's a good thing for those of us in colder climates where it can be difficult to thread the webbing thru the buckle when it's cold and dark.