I hunt out of an Alumcraft ducker. It is lighter than the Mud Duck boats. It drags okay empty but becomes a chore if you leave deocys and gear inside. Plastic type boats drag easier. I expect the Mud Duck to be a tougher drag, in addition to being heavier the sides are more square. You would have to confirm with someone that owns one though. I looked at one and spoke with the owners a couple years ago, can't remember cost but I think it was similar to a used Ducker.
If I remember correctly, the reason the Ducker production fell off and nobody picked it back up was the high cost of the boat. They used an expensive grade of Aluminum to enable making the bends/curves of the boat. Some prodcution changes on the newer models made them less expensive but also lessened the strength of the decks and the boats appeared cheaper. I have both an early and a late model, hunt out of the later one.
All that being said, if I were in the market I would certainly be looking at the Mud Duck. You may also be able to find a Lund Ducker, they run less than the Alumacraft but are heavier.
A friend of ours has a Puddler, drags easy but we are always wondering if he's going to drown if the wind comes up. Not much free board with him (160#) small dog and a dozen decoys. I think Lumbertick paddled it a few times and he was not impressed. For the mid-size water we hunt a larger size Carstens would be safer. I am paddle challanged and prefer oars