Having done a fair bit of research into this, including speaking with Don Jordan several times, I would recommend the JSD, rather than a parachute-type sea anchor. A sea anchor, by definition, will impose far greater shock loads on the boat. It can, if not deployed properly fail to open or foul itself on the trip line, which most parachute sea anchors have. Also, the points about the boat still wanting to horse around while on a sea anchor deployed off the bow is still a very valid one.
The JSD, has a few attributes that make is much better for the boat and the crew, especially in a survival-storm situation. First, the long length and small cones allow the JSD to gradually load up as the slack is taken out of the series drogue's rode. This means that the shock loads are much lower—reducing the chances of damage to the boat's hardware. Second, the boat is oriented stern to the wind, which makes it less likely to horse around—this is especially true of modern fin keel designs. Third, the JSD is designed to be a "fire-and-forget" device of last resort—giving the crew a chance to rest in relative safety. And finally, since it is deployed off the stern of the boat, does NOT REQUIRE someone to go forward to deploy it in storm conditions, as most parachute anchors would.
The main problem with the JSD is retrieval. It is a bear to retreive unless you're in dead calm conditions. To retrieve it, I recommend having two long lines that are lead forward to snatch blocks near the bow, that are long enough to come back to the stern of the boat and reach the winches. Tie one line to the JSD rode, and use the winch to pull that line all the way to the bow, retreiving about a boat length of drogue. Then tie the second line to the drogue and do the same. Then untie the first line and repeat. By using two long lines and retreiving nearly a boat length at a time, you can reduce the amount of effort and time it takes to retreive the drogue. If you have two people aboard, one can be untying the lines at the bow and running them back to the cockpit, while the other is winching.
BTW, the JSD really needs to have its own set of "chainplates" added to the boat for it to fasten to, as most cleats aren't really up to the task IMHO. When making a bluewater passage, the drogue should be stored, with the bridle attached to the chainplates, in a bag or locker near the stern of the boat—ready to deploy.
I have used a JSD and have practiced deploying and retrieving it on several boats, including my own. They're bulky and a PITA to retreive, but by all accounts, including some from friends of mine—they're worth it in a bad storm.