I also have a Shoreline Marine rounded paddle which I can get more power out of due to its larger blades, but it also takes more effort to use and I get wetter using it. The Harmony Drifter looks very similar to the Bending Branches Whisper, but after trying a BB paddle, I found the Harmony to be lighter and in my opinion smoother to use and of course cheaper.
This last weekend I was out on the local lake with some with some boats kicking up 2+ foot high swells and the kayak handled it like a champ! I barely even got wet! Plus there is tons of storage space on this yak. I'm planning to buy a second one for my wife. The molded seat is pretty comfortable. There are scupper holes in the seat, but if put in the included plugs you should stay nice and dry.