I have never owned a Red Dot Scope, but have an interest in one for a 44 Mag rifle. Is there unlimited eye relief? Is there any parallax to worry about and if there is, what are they set at? What size of Dot do you recommend, and why. What is the difference between a cheap Red Dot and a better type of Red Dot? Is there any advantage to a large diameter vs a smaller diameter body? Do you have to sight down the body like a scope or can you shoot accurately with both eyes open? I thank any one that can answer any of these questions that has had experience in the use of Red Dots. You can answer that you would not have one under any circumstances, just tell me why.