The brightness figure is the whole argument for this projector and it is an unusually well-attested one: an owner who replaced a 4,000-lumen ultra-short-throw with it posted before-and-after pictures thirty minutes apart and described the earlier projector as simply not as bright as expected. In a living room with real daylight, that gap is the purchase.
The details that owner raised turn out to matter as much as the picture. The projector it replaced had no screen trigger, so a motorised screen could not roll up and down with it, and it would not integrate with his home-automation system. This one does both — which is the kind of thing nobody puts in a specification comparison and everybody notices after installation.
The cautions are price and timing. It arrived with almost no independent testing, and owners repeatedly held off until reviews appeared. It also costs considerably more than the established rivals, one of which regularly discounts to around $3,000 — a gap owners weigh carefully against the extra 2,000 lumens.