Mine is a cheap one, a Tasco Reddot. Theisen's had them on sale a couple years ago so I thought I would buy one to try it. I have an astigmatism (my eyes blur at long distances), so rifle sights don't work real well for me. I tried a regular scope but wasn't real happy with it. I felt like I was missing out on some of the quick shots because I was taking too long to aim. What I really like about the red dot is it's pretty much just point and shoot. Both eyes open, don't worry if you didn't settle the gun in right, if the dot is on you'll hit it. I sighted mine in at 100 yards, and love how acurate it is. I have shot six deer with it, and two turkeys.
Like I said before, I have never had a problem with batteries, regardless of temperatures. I leave mine on all day when I am hunting. I hunt second season shotgun, and the late doe season, so I have had it in some cold temps and bad conditions.
Mine does have windage and elevation adjustments like a regular scope.
-Matt