Works okay, but don't think it works much better than memory foam/gel cushions half the price.
Purple mattresses might be good for sleeping on (never tried one for that though), but I don't feel it works well at soaking up road bumps.  I had extensive spinal surgery (double laminectomy in the thoracic and double laminectomy in the lumbar, plus a fusion in the thoracic) a couple of months ago, and just started going back to work. The bumps and jolts on my forty-minute drive were making me terribly uncomfortable and sore afterwards.  The basic gel/memory foam seat cushions were not doing the job so I tried this purple cushion.  It might be adequate for static chair use (but it is of course quite pricey). But for absorbing jolts in a motor vehicle, I don't really feel it is worth the price. Better than nothing though. I plan on trying an Ergo21 Liquicell seat sports cushion next (yet another expensive attempt to soothe my aching back).
Rating: 3 stars