The System EX is cheap, but unfortunately not very comfortable. Despite the listed 45mm of travel, even deliberate ball-busting bounces on the saddle never coaxed more than 25mm of movement out of the shaft.
On the trail it rarely moved at all, except over bumps that we would ordinarily have stood up for rather than stayed sitting through. What give there was did little to reduce the eye-watering consequences either.
The plus side is that there’s no bounce or movement when pedalling. With no spare spring kits available, it’s only big, heavy riders who could really regard this as a viable option for a suspension post.
There’s increasing fore and aft wobble and knock from new too and there’s no way of reducing that play as it increases. It does come in a decent range of sizes, though.