They're light, elegant, cost as much as Ferrari.

I wouldn't have blocks flapping on the sail.

We hae a main that about twice that size, we have a Dutchman system, Spectra sails, and use a line that runs from the after boom blocks up to the reef and then is tied to boom.

If you were doing speed reefs or reefing a LOT, you might justify doing something more elegant -- but I wouldn't if I were you John.

A single line reefing is too complicated for my taste. I prefer a line for line for clew; and, a line for the clew (unless you just use a reefing hook at the gooseneck). With the single line reefing, if something goes wrong with the lines or the blocks in the boom, you'll have a hell of time sorting it out.

As for the lines, I think the issue with the line size and sophistication with the reef lines really is i) handling and ii) (if you're going a long way and reefed) abrasion on the line. Having a VERY LOW stretch, high-tech line is usually not as important as how well you tie the reef in. That's really an issue of your technique, getting the sail and boom tied down nicely, and attention to sequencing when you set-up the reef. I've seen clews pulled out of some sails by applying an agressive winching down improperly.