I've been using red dot sights for over twenty-five years and I've owned dozens of them. I used them on most of my competition handguns and all my hunting handguns now days. There is no difference in quality and life span. The good ones last and the cheap ones don't. The mini (reflex) redots work great, but they are a bit harder to find the dot with if you're in a hurry and don't shoot them a lot. The tin can style are a lot easier to find the dot in, it's like looking through....well, a tin can open on both ends. The mini sights don't have a lot of adjustments or reticle options. Some of the tin can sights offer different reticles, different size dots, and a large selection of brightness settings. The quality ones in either style can come with a lifetime guarantee and the companies don't have any caliber restrictions. They will tell you right on the phone that you can put them on ANY caliber of rifle or handgun and they are guaranteed to last. And, in fact they do last. I've put both styles on 44mags handguns and 45-70 rifles and they held up just fine. Now days batteries last a very long time in them. I often get two seasons of target and hunting out of a battery. Carrying a spare is really easy, they're very small and easy to change in either style sight. If you haven't used one before, I'd suggest the tin can style. For my hunting purposes they seem to work out the best. You can put see through lens covers on most of them. The small mini sights don't have good lens covers. At best you get a little "hood" that can come off quite easily when carrying it around. I've used both in steel plate shooting (which I was very good at) and to be honest, they worked equally well. The smaller ones seem to have a "cool" factor that actually didn't translate into being better. Hope some of this helped.