I have been riding a Race Face (Easton) dropper this season on my single speed rigid Niner. I really like the post... prior to that I rode with a Thomson dropper for several years and that is also a great post. I can not speak to other brands as I haven't any experience on them but will say you can't go wrong with either of these two. I love my dropper, use it constantly. When I was riding geared I found I used the dropper more often than I used my rear derailleur.