I use a Sightmark Mini Shot on my 590...
As for performance, this thing is a little beast!
What it lacks in size it more than makes up in results on target. Windage and elevation adjustments are made with a small screwdriver. Took me about five shots to get her dialed in and I was punching holes where I wanted em in no time. Here's one of my 50 yard targets using Centurion 2.75 inch, 1 1/8 oz slugs. Ten rounds went into this one...
Put 50 rounds down range today with no movement or vibration in the optic or mount. I highly recommend the Sightmark Mini Shot to anyone looking for a great, affordable reflex red dot.