[4runnerman]

I guess one other question I have is whether most/all modern day scopes retain their zero reliably. I know some cheaper red dots have problems with zero creep. I don't want to get something somewhat cheap and then find out that it doesn't retain zero. What types of characteristics affect this

This i have found is where Quality (cost ) comes into play. To get great tracking you are going to need to spend some green. If you sight your scope in and use hold over you will be safe with a mid range scope. Do the box test when you get it sighted in and you will see right away what kind of reliability you are going to have.