I am on my second set of the GP 4000 S ll tires. I got a little over 5,800 miles on them before I rode over something that sliced the front and I have over 3,400 miles on the second pair. The thing that stands out the most for me is the high quality of the ride. For many years I rode on Gator Skins and would typically get 6,000 miles on a set before I would change them, but the ride is quite harsh. I ride quite a bit of rural chipseal roads and the GP 4000 S ll really take out most of that annoying vibration and buzz - I was amazed! I was able to ride further and faster because I wasn't as fatigued. They are kind of expensive, but man! the ride is worth it.
I've got over 2000 miles on these tires on my recumbent and I have been very happy with the performance. The tire is much lighter than the stock tires that came with the bike, which helps going uphill. On my rims it's closer to a 25 than a 23, which makes for better road contact and a more sensitive road feel, which helps my confidence going downhill at 50 mph. So far I have no big cuts or knicks, and haven't had a single flat due to puncture. My rear tire is close to the wear mark limit, so I'm ordering a new pair right now.
I've got 1000 miles on these tires so far, including 5 miles of gravel road, with no flats, nicks or cuts and minimal wear. They grip the road well, and though they are listed as 23mm wide I find they are closer to 25mm on my rims, which gives a softer ride than the similar Kenda tire. A reasonable balance between weight and reliability. I will buy these again.