-- Last Updated: Oct-03-12 10:27 PM EST --
Not sure it is Valley Dilemma, as Valley is a niche player. If you go by numbers of boats sold, SOTs and rec boats more than beat out touring boats, where Valley is just touring (and even within touring, Valley is a bit of a niche player, as none are ruddered boats).
There are niche players in other markets also, such as Cobra and Hobie (SOTs).
I think if you look at the major players out there and what they offer (Johnson Outdoors, Confluence, and Legacy Paddlesports) you will see what the meet the majority of the market strategy is.
Edit - my bad. The OP did say "sea kayak" for the masses, not just kayak for the masses. So maybe Delta or Eddyline would be better examples, though they are both 1 material brands (where to fulfill the wants and needs of the sea kayak masses, you would definitely need rotomolded plastic and a higher end material.