Ken, I have had a S1000 for about a year on a 21' and what Yankee Clipper said is right on the mark. Mine holds ok below 2mph but you do need to be over 2.5 to get it to engage. When they first came out they would shut off at low speeds but then Raymarine updated the software to work down to about 1.25. I understand that you can have the older units updated if you send in the brain.
Installation is pretty easy. My only complaint would be that the pump is fairly noisy even after insulating it. Still quiieter than having the wife steer.
Mudflat
