I wouldn't consider any that won't cowitness. Burris FFII will but the on off button malfunctions. Deltapoint will, not aware of any problems. JPoint will, the glass is more like plastic and when it scuffs, becomes hard to see through, so you have to treat it like a baby. RMR, not aware of problems and you can get an on off model. And the Docter, those things are great, not aware of major issues.
When wanting to use just the irons, it sucks to have one that doesn't shut off, as I am experiencing. The thing is, I wouldn't spend the money on the RMR if it's just a toy.
If you're buying new, I'd go for an RMR. If you're buying used, I'd go with a JPoint, or Delta Point. They both go for 3-400 but I see em used often for 130-240.
I plan to get the on/off RMR sooner or later, but I use a JPoint right now. The Delta has a bigger lens but takes a smaller battery. The JPoint takes a cr2032 which is cheap and common and since I use an Aimpoint T-1 on my rifle, I can use spares for either.
Uhhhhhh, just trying not to forget any potentially helpful information...
Oh, audible clicks. JPoint is the only one where the windage and elevation is like a constant turning of the dial. There are no clicks. It may P you off but I don't mind.
I believe it's the Delta Point, but it may be another. The screws to lock the windage and elevation are on the back of the sight, so you won't be able to get in between the sight and the rear irons to use em, unless you innovate a way to do so.
The Burris FFII has a slight magnification and an amber looking view through the lens. It is very prone to impact and will break even during transportation if it takes a hit. I've read of a guy that was leaning his rifle up against a tree and it fell and cracked the sight. Luckily, even after warranty is up, he got it replaced.
I think that's about all I know about these co witnessing sights.
DO NOT BUY THE BURRIS FFIII!!! Or buy it, but it's been my experience that, if you actually get out and shoot enough, you will find that it shuts off on every shot. The battery door is on top and it is cheap plastic so you can strip it if you try and tighten it. This results in the battery door coming loose and recoil turning it off. Sure there's locktite, but like I said, it's plastic. I wouldn't want to risk messing up the lid when replacing the battery. I say don't get, but others may LOVE it.
OH! Lastly... Geez sorry it just all keeps popping up. One thing to consider, is ambient light sensor. They all work well, but the JPoint's censor is faster than the Delta's. Not sure about the RMR. Thing that sucks about em, is if you use it for home defense, or train in low light no light, you will lose the dot in the flash light, because the censor won't react to the flashlight. Not a big deal if you train with irons. Just a thought.
My personal opinion is that the adjustable on/off RMR's are the best. Even though it's not like your going to adjust the dot in a stressful situation, you have the option to turn it off and adjust for range, set it at a level for home defense at night, and whatever else.
Otherwise, and as previously stated, for your use I would recommend a used JPoint, or Delta Point.
Hope this helps.
AHHHHHHHH!!! ONE LAST THING, I promise! Even the tiniest scuffs on the JPoint lens WILL make the dot look blurry, or pixelated, in a way.