For an inexpensive dropper/suspension seatpost, the Exaform 861 works well. Makes the seat height easy to adjust and provides some cushioning. There are two negatives. the externally mounted cable is about 4 inches too short. My ebike has a 2 3/4" handlebar rise, so the cable is stretched out of position. When I place my rear end on the seat, it lowers about one inch.
Seat was very difficult to adjust for my height and then sometimes just slowly drops down. It doesn’t stay where I adjusted it.
Kind Shock ExaForm 861 Suspension Dropper Seatpost
Didn't know the seat post sags a little after extending. According to Shannon, "That's the way that one works!" It's not bad, but not what I was expecting and disappointed from others I tried. I would have spent the extra for the internal cable if I had known. Also difficult to tell from the photos that this was inverted and the cable is outside.