Most impressive. While these last couple three years most 3LCD and LCoS 3 chip designs in the HD91's price range address the inherent minor mis-convergence of their 3 "chip" configurations, with digital alignment solutions, it's not just as good as starting without any mis-convergence. Overall the HD91 produces a very sharp image. It does a very nice job edge to edge with very little softness even in the corners.
Take a look at our two pair of images above. In addition to the native sharpness, the Ultra Detail was turned on. To the On setting, not the over the top HD+ setting.
Following the closeup of the HD91 on spiderman's wrist gadget is the same basic image from the BenQ W7500 (another DLP), the JVC RS4910, which is a $5000 3 chip LCoS projector, and finally an Epson Pro Cinema 4030, the model below their UB series (we didn't shoot this image with the 6030UB). And for fun, the last one is the $27,000 true 4K Sony VW1000ES (a 3 chip LCoS) (look at all the texture). The magnifications vary slightly as do the frames and the brightness. Have fun comparing.
The HD91 is one quiet projector. The spec sheet says 23 db. Remember that the HD91 doesn't really have an "eco" mode. It is anywhere from much quieter to the Epsons and should also be noticeably quieter than the JVCs and Sony's out there, but not as much. Bottom line - few projectors will be quieter. No problem.