I am about 180, so no issues with the weight limit. Average seatposts are usually 200-300 grams and these are 350-400 grams. So, there is a weight penalty, but not much of one. I rode my fully rigid MTB on very rough trails today and yet again this thing amazed me. Being that this bike is a SS I am out of the saddle a LOT, but still in the saddle at times in which there are big bumps, just no way to avoid it, and this saves my ass and back. Also, it makes it much more possible to keep the power hard into the pedaling in place of getting bounced and losing momentum.

By the way, I looked at these for a LONG time before going for it. Now, I like it so much I would pay even more for it if needed.