If you have to "move around" to see it, it's not a uniformity issue. What you are observing is different gain from different positions. Uniformity differences are visible from a single position; your viewing position.
The question lies in defining "proper setup", and that's rather ambiguous. Ideally with the HP, we all know that it should be placed as close to the viewers eyes as possible, but at what distance does it slip from "proper" to "improper"? There's no hard and fast rule, but rather just a gradual decline in gain and uniformity, and it's up to the individual if the results are within their requirements or not.
Ceiling-mounted setups are quite common, and there are many posts in this thread with users asking about what sort difference they'll see with a ceiling mount versus a mount closer to eye level with the HP.
Commonly, the answer is "less gain", but in reality that's only part of the answer.
Also, this effect is not something you can "only" see with a solid colour. It's just very easy to see it that way, as with testing any screen for uniformity. It's always visible, just not always distracting. The more it can be mitigated with careful placement, the more subtle the effect will be, and the more it will become a non-issue.
But by default, it's another of the variables one should consider when deciding on their individual "proper setup".
I enjoyed reading many pages of this thread. I liked all the feedback and no wonder why this thread has so many pages. Dalite support is also excellent patiently answering all my questions.
I have JVC RS40 projector and about to order 142 inch diagonal HP screen today. My wife complained that the light from the projector lense is falling on her eyes whenever she stands and she does not like that. She is not sure how harmful these rays are. She wanted to put the projector wherever possible without needing her to be careful whenever she stands.
I really wanted to try this screen. I told her that we can click hide button on the projector to prevent rays. She did not like the idea.
If I have to place projector higher and if screen behaves like standard screen, I don't have problem. I want to have an option at least to watch 2.4 if needed.
Appreciate any feedback on the placement. I can't wait to order to enjoy phase 2 of the my projector to use screen instead of wall.