This is a reasonable number for such a long zoom, although given the projector's somewhat limited brightness, it's wise to mount it as close to the screen as possible. Perhaps most impressive, the scale of the content from 1080 lines to the projector's native 4K matrix was truly outstanding with the default settings of the super-resolution reality creation feature. At the top of the range, you'll find a better step and that's the Sony X1 Ultimate for Projector. Traditionally, most projectors use high-pressure mercury lamps, but more recently, LED and laser projectors have arrived.
Sony's manuals are quite cryptic when it comes to helping you determine the correct range in which your projector will properly occupy the screen. In this regard, it does a better job than most projectors by actually expanding the projector's dynamic range rather than simply increasing the lights at the expense of illuminating dark areas. During shipping, it is very likely that the 3 panels of your Sony projector were slightly misaligned. Today, the fastest gaming projectors have an input delay of less than 10 ms, but anything lower than 30 ms is still much better than most projectors and suitable for most gamers.
The X1 for Projector brings frame-by-frame analysis, developed for Sony's Bravia TVs with X1 technology, to the big screen. The previous native 4K projectors are Sony's most current models at any price, but you'll also find their predecessors available for a while longer. I suppose that Sony's high-end projectors with irises or lasers can also see deeper blacks depending on the content. Sony is one of the biggest players in the native 4K projector market, and each model is replaced only every few years.
The good news is that these older machines are still native 4K projectors with Sony's SXRD panel technology and an X-series image processor. Native 4K means that each pixel on the screen is represented by a different square in the projector panels inside these machines.