Resin versions of the ships are hand cast by me or Trollforged Miniatures. They are super high detail but may also show small imperfections from micro-bubbles or mold seams. They are unpainted but hold paint very well. The resin I use feels drier and more brittle than Trollforeged' proprietary material but is otherwise similar. I would recommend these for the collector, those who want to do a detailed paint job, or who only need one or two ships. These come with a flight stand while the plastic ships do not - though they are available from Litko.net.
Plastic versions of many ships are available in sets from the Shadowstar Corsairs board game. These are mass produced, injection molded plastic - similar to other game pieces and mass market miniatures. The detail is still really good but the material feels a little softer and slicker than resin. There are two color schemes, mask-painted by machine in 3 or 4 colors; and unpainted sets (I'm not certain how well they will take human paint). They also have that "new-miniature smell" right out of the box. These are available only in sets, and only while supplies last. Still, I think they are clearly the best choice price-wise if you just want a miniature on your table and the ship you need is part of Shadowstar Corasirs fleet. A plastic set costs more than a single resin ship, but if you want three or more ships you'll be saving money. Six of the ships in the set are already on posters and I plan to "posterize" the other three or four in the months ahead.
There is more information on this subject in Update #1.