Given the number of suspension seat posts mentioned here (and I'll probably join the crowd soon), I suspect I'm not the only one to have noticed this, and I'm simply curious about why this seems to be so.
Mainly, I've been surprised at how jolting the ride on my Vado can be. As an example, there are some concrete streets leading out of my subdivision that I traverse often. Over the years on the older parts, some of the slabs have subsided a bit, leaving about a 1/4" sharp-edged lip when going from one to the next. Riding over these on the Vado it feels like someone's hammering on the base of my spine, which is admittedly tender at this time. Similarly, one of our unpaved rail-trails has a surface with a lot of small stones embedded in it that produce a continual very rough ride.
I remembered that these were not exactly smooth on my other bikes and that I had particularly complained about the trail before, but when I finally got out on my Specialized Crosstrail the other day it was actually very different. The Crosstrail is similar to the Vado in geometry, maybe a bit more of a forward lean, but it has an aluminum frame and rigid seatpost, plus skinnier 700x38 Trigger Pro tires at 10-15psi more pressure. But it went right over the slab joints with much less of a bang, and riding on the trail the ride was smooth compared to the Vado.
So is the difference in ride due mostly somehow to the difference in weight, the Vado weighing about 2x the Crosstrail? Do the Vado tires have stiffer sidewalls? Or maybe since I have to pedal the Crosstrail with more effort, it lifts some of my weight off the saddle?
It does make me more sympathetic with my wife who complained a bit last year about similar issues on her Trek Verve+ compared to her analog Verve, but the Verve+ actually comes with a telescoping spring seatpost (as does the new Vado LTD). Hmm...