Had a great experience with my pair of Mafate 3s. Was actually hesitant to buy the 4s but so far I am pleasantly impressed with the new version. Did several trail ultras including the SCAR (75mi, 19k ft elevation gain and loss) in the previous version and had great use out of them so the 4s had some big shoes to fill (see what I did there?).
I've only worn them on one run and a couple of short hikes so far but the fit/comfort is just as good if not better than the Mafate 3s. I'm hoping they are also as durable as the previous model but only time will tell.