How long does Accoya REALLY last? Manufacturer says 50 years but I want to hear from actual owners.

Looking at Accoya for a full re-side (2,200 sf) on our 1970s cape in coastal New Hampshire. Manufacturer claims 50+ year above-ground lifespan and 25+ in-ground. That sounds like marketing. What's the real-world experience? Also, is the length limitation (I've read max ~16ft) a problem for siding? Our longest unbroken run is about 22 feet. What do people do for the long spans?