I’ve ridden my normal, old fashioned GD for about a year, and it was a couple of years old when i bought it. It has been pretty much hassle free, except when it wwas broken by a stupid bike shop in France. However, this experience served to show the frankly incredible service from the GD folks who fixed everything FOC, even though I clearly stated that I’d bought the seatpost second hand, and that it was damaged by a bikeshop.
I’d highly recommend them for hassle free riding. I also own a Reverb, which is a superior piece of kit – the infinite adjustment is excellent and the 5 inch drop is very useful. But ive only had it a few months, so cant comment on the longevity. But I’d be really happy to own another GD.