I found the seat to be quite comfortable and I really liked the roomy cockpit. I am rebuilding my fleet and looking seriously at another Viking, a Glider or an Epic 18X Sport.
On a normal flat day w.o extreme tides or winds the boat cruises at 4.2 knots with a medium paced paddle. At one point in Crystal River FL I was riding out some "surf" from large boat wake... When the boat rode them correctly I hit 5 knots!
The boat is EXTREMELY comfortable for a touring boat. I have some space to keep my knees somewhat bent.
Beautiful, sunny, no wind yet, glassy water with a soft swell. I became one with the day’s groove and the Viking.
On the way back it eventually became interesting 1-2 ft. (and bigger) chop, whitecaps, with tidal rips creating sometimes confused seas that kind of stand up any old where. The nose of the kayak would sometimes punch through a wave, and in return, a wave sometimes washed over the deck. Did I mention I'm pretty new at this, that is, kayaking? I have done some canoe paddling and windsurfing on these waters, but the kayaking is surely a different experience and set of skills. The Viking did great through all this, never feeling like I was on the edge. I suppose that's what they all say before the wet exit practice...
I'm sure there are faster and sleeker, but we kind of match that way. I'm 6 feet and 220. Everything seemed to fit pretty well. I'll have to remeber to put the rudder up before beaching, but it was sturdy enough to stand up to that abuse. Consider the experience level of your source, but the Viking was a friendly ride that I recommend.