I have tried a few of them. I have the Bushnell TRS-25, Primary Arms Advanced Micro Red Dot, EOTech 512, and most recently, the Sig Romeo5. The Bushnell has a small field of view, and the LED sticks up too much for my liking, taking up some of the field of view. It is however probably the best budget choice, as it can be had for less than $100.
I like the EOTech, as they don't emit any light out of the front, but I don't like the fact that they have to be manually turned on, then the intensity set. IF they were motion auto wake, and came on at the last intensity setting, they would be perfect.
The Primary Arms Advanced Micro is a very good red dot. I like that it is brighter than any previous red dot I had bought. On a sunny day, outside, its the one that doesn't wash out. You can still use it. The others just don't have enough intensity. It comes on with one touch, and at the last intensity setting
I recently bought two Sig Romeo5 red dots. I think they are perfect. They are very similar to the Primary Arms Advanced Micro, with the very important addition, they Auto Wake. Turn them on, set the firearm down, and after 2 minutes, the dot turns off and the unit goes into sleep mode. Just the slightest movement, and the dot comes back on at the last setting. I have tried this many times, and it works perfectly. The Sig also has the brightness of the Primary Arms Advanced dot. I have these two Sig Romeo5s on my AR pistols, a 7.5" 5.56, and a 10.5" 300 BLK. The Sig also ships with two bases, a low base that works great on pistols, and an Absolute Co-witness base that is perfect on an AR with Magpul MBUS sights. The Primary Arms dots only ship with one base, and to use on an AR, I had to buy the higher base, at a cost of $30.