I'm another satisfied Shuttle Slide user. I also bought the heavy duty SSD-HD9..
I did not have enough room with the factory Rhodan puck to get it to drop and get all four bolts thru the deck. With this unit, I now have six 1/4" bolts, a backing plate, fender washers and nylock nuts. It's pretty secure.
I also like the fact very little of my Rhodan is hanging way out over the bow. It retracts nicely.