Duckies are great. The difference seems to be between the wide rafty type (Hyside Padillac) and the narrow pointy kayaky type (lots). Both share a common ill— they fill up with water faster than the self-bailing holes can drain them.
When I've run with duckie folks, quite often they have to pull off between rapids to let their boats drain.
The other problem is comfort: you need somewhere to brace your feet and a good back support, and quite a few duckies lack one or both.
For 20 years I've been paddling Pack Cats and Fat Pack Cats http://www.jpwinc.com
on all sorts of water from really low drag-over-the-bars to the Grand Canyon (below).
(photo by Jack Kloepfer)
To the Escalante River in Utah—
I took a Pack Cat on the Alaska Ferry to Sitka in April and paddled around (w/wetsuit and double-thick booties) during the herring run surrounded by orcas, bald eagles, sea otters, sea lions, and humpback whales. Took the same boat on a freighter to New Zealand to paddle rivers, lagoons, and bays. It packs in a duffle bag: a one-hand carry.
What I like: instant self-bailing, easy self rescue, simple to rig camping gear, take apart for easy packing & storage, incredibly comfortable and adjustable seating position, and rugged construction. (I've got four sets of Jack's cat tubes and have never had a puncture.)
No, I don't work for the company— I just think they're the best small backcountry expedition boats you can get, anywhere, at any price.