FWIW, I fittted a Simrad TP22 to #199 and it worked very well. Set the socket into the starboard cockpit locker cover with a 1/2'' thick hardwood block epoxied underneath for backing. Had the remote, and many times sat on the foredeck and steered. Also, I wired it to feed from the Garmin 76, and it would sail to a Go To point with no problems. A strong performer, it was dependable for me, and I found factory support to be, well, supportive. It worked best flying as large a genoa as possible, which the Ariel liked anyway, as that setup reduced it's weather helm.
I also had read the reviews, and was wary, but had no problems.
I also fittted it to my 30 foot Flyer, and it works ok, but with the outboard spade rudder, it has some difficulty with the weather helm under anything but light winds. Under power, it is fine.
ps: I DO miss that sweet Ariel.
Dan