I have an astigmatism as well and find it really depends on the site. I have 3 Burris FFs and they are a big red star burst to me, so I put electrical tape over the light sensor to dim the dot and it gives me a perfectly round dot for precision. Way faster than iron sites for me personally.
I had a trijicon mini reflex as well and it was worse than the Burris'.
I know you guys really frown on cheap stuff, but I know a couple fellas that have cheap reflexes on ARs and surprisingly both were very clear to my eyes. One was a Bushnell First Strike that was basically nearly identical to my FFs, the other was a Truglo Open Dot reflex. Both had really clear round dots for me. Kinda bummed me on the FFs. I've been toying with buying the Delta Point, but just afraid it will star burst as well.
