Hi Mike,
I have used the Sightron and found the AO was very, very good. the adjustments were 1/8 as advertised and the image was clear. The eye relief was a little short and the scope was heavy.
The Weaver HBR was very good also but once again had a short eye relief. The adjustments were 1/8 and the AO worked well.
The Burris HBR I felt was superior to both if for no other reason than the longer eye relief. I shoot the full 308 so such things are important. If the Burris has a shortfall it is the fact that the detents for the 1/8 adjustments on some scopes is mushy. However I prefer the Burris to any other 6X I have tried.
I prefer the dot. I seem to find it easier to "make the hold" for condition adjustments and seem to be able to center the dot better than I can the crosshair. Of course I realize my old eyes see bigger things (the dot) easier than they do the small things (the cross hair).
Larry