I have a few pieces that have seen some use - tents, ground clothes, tarps. A couple of pin holes from wear on top of an expected tear or two that probably would have happened with silnylon or whatever fabric.
my brother is an ultralight hiker and has a dyneema pack that he shredded up a bit with a few yeasr of good use. Easy to patch and I think chewed up dyneema is a bit of a badge of honor in that crowd. I bet if you check some of those lightweight forums, there is some good feedback on long term use.
one other comment, I think most dyneema gear is going to be built with a specific focus on weight. therefore, in addition to the dyneema, the gear makers are cutting weight elsewhere as possible. That means they probably trade of some durability to save weight on things like zippers and netting, etc. so you end up with a piece of gear that has zippers that are a little more dainty and harder to use or maybe netting that is thinner and snags and tears more than conventional gear. So, while the dyneema fabric may hold up comparitively well the overall product is going to have a bit less durability than something more conventional but also likely quite a bit heavier - ie. don’t buy a 2# z packs ultralight 3-person tent made of dyneema, angel farts and helium thread and expect it to last as long as a 10# hilliberg expedition tent.