On a 60 or 75 inch screen as is typical in a conference room or classroom, the Q7 can do a nice job as long as there is some decent control of lighting.
In this review we show a couple of pairs of images, with and without the rooms window shutters open a good bit. We are projecting a 60" diagonal image on to my 1.3 gain screen, which would be a fairly common level of gain, both in business and at home. We did not use the brightest mode: Bright, but modes putting out between 380 and 483 lumens. And the Qumi still did a respectable job.
Note that the first two image pairs are relatively dark scenes, one pair is of a photo of evening dusk, and the other a very dark looking website page, in other words, tough images if there's ambient light. Then come three images showing the lighting in the room when the images with ambient light where taken. And finally, that same coastline photograph, used in the previous images, with the shutters open as shown. Because it's a nice and bright image, it remains vibrant even with that ambient light. BTW ignore the 4K markings on that coastline scene, the content was 4K, projected on a 4K Sony projector, but the resulting photo of the screen was resized downward, and converted to jpg. It's only 1000 pixels wide, about 1/16th the resolution of the original 4K, which is why it's not really sharp here.
The last image - a news site, using a browser, is a bright image. It was taken with the same ambient light present as the first image. Lesson: Medium and bright images are easy. Dark ones are always more challenge, even if you have thousands of lumens!
Ambient light handling overall? Not bad, in fact, impressive for such compact projector!