I have Aimpoint and EoTech red dots on my ARs, but I've shot a lot of rounds with Trijicon, Holosun, Primary Arms, and Sig (probably others). For me, they all are good, or at least not bad, in terms of glass quality and clarity. I see the dot on the target. I've heard people comment or even complain about the tint of the glass or even a slight magnification. While I've noticed those things, they don't bother me.
Now for LPVOs, glass quality and clarity is a more significant factor. That said, there's also a level of "good enough with my budget" that one needs to consider.