I have to say the original title and inference of this thread frustrates me.
As if surf/ocean skis are somehow more evolved versions of sea kayaks, with the enlightened converting and the luddites still in their kayaks.
If your only criteria is (relatively) short downwinds as fast and fun as possible - sure, ocean skis are superior in every way. Skis and sea kayaks are of course built with different/ though overlapping objectives. They handle differently and optimised for different things. Surf/ocean skis evolved from surf board looking craft and sea kayaks from Inuit hunting craft. May I suggest that if anyone transitioned from a sea kayak to an ocean ski and never went back to the kayak - that's great, but they were likely never using the sea kayak fully for what it is intended, in the way it was designed for. Sure, probably many sea kayakers use their craft only as flash recreational flatwater kayaks, though I also know plenty of ski paddlers who are nervous in more than 2 ft chop. It's all good - plenty of Porsches are only used for the daily commute and run to the shops as well.
A sea kayak is not designed for and will never win the Molokai Challenge - though that some designs are fairly fast and might even reel in a couple on the backline with the right paddler is a wonderful thing. Similarly, an ocean ski would never be a good choice to undertake a trip like this
www.laurie-ford-kayak.net/maatstra.htm - even if some ocean ski's are being made to work for light overnights and supported touring - which is also a good thing.
BTW, I do like the ski community (they are often more open minded then old school sea kayakers) and paddle with ocean skis (often as the only kayak) as much as I do with other sea kayaks. Most of the better paddlers have both, which is I think the optimal solution, and something I would do if I had the space and time to master two styles of paddling craft.