Both look very similar which one do you guys have experience with and/or recommend? A micro red dot will be the optic(holosun, primary arms, Romeo).

Having used both, the Attero is the winner for me. I preferred the mounting system of the TWS, but overall the Attero looks/feels more solid.

I will say Attero. But that is only because I have one. Very solid and well made.

I went with the picatinny version because I did not want to commit to one specific optic.

How solid are those mounts?  Do they hold zero?  How are they tensioned down? The leaf spring for the rear sight?

Mine has been 100% good to go for several hundred rounds. I mounted a Burris FF2 on it and it's a very fun setup. It was pretty simple to install no issues on my part.

This video shows the install there are a few other videos around aswell.

Have not tested it yet but just got the Artero B and it mounted easily with a Romeo 5, I like the co-witness feature.  Feels solid but the shooting part will tell...

I have the Attero Bravo on my SLR-106 with a Sig Romeo5 on it. Once you knock out the rear sight and leaf spring you drop in an included plate nut and tighten down a screw. Obviously the front part of the mount attaches and pivots where the rear sight used to. Once it's installed and the screw tightened down it is very rock solid. Maybe I was lucky but the mounts rear notch lined up perfectly with my front sight both windage and elevation and is good to go out to 85 yards (furthest my range goes). I really like how low it puts the RDS so that you can keep the appropriate cheek weld and also still have usable back up iron sights. I believe that you are supposed to be able to keep it locked down and still remove and reinstall the dust cover, but for some reason on my AK I cannot reinstall the dust cover so every time I need to clean the gun I have to break the Bravo's screw loose and pivot it up out of the way. Even still, it seems to go down to the se place every time and hold zero.

I had the same problem with my Attero mount. It was against the dust cover when tightened down and there was no way it was going to be removable. I ended up taking a file to the underside on the mount to give it just enough wiggle room. Its tricky to get the dust cover back on but it does work.

I went with the TWS mount.

I'm unhappy with it.

The handguard release lever cannot be operated as the pin is in the way.  I could probably reverse the pin and put the side with the c-clip on the side with the handguard retainer lever but...I dunno, i read the instructions and it says to install it the way I did.

I also dont like the c-clip.  Its barely in the recess on the pin and the c-clip stretched out something fierce when I installed it.  I anticipate the c-clip breaking at some point.

The mount is also not parallel to the bore despite being installed properly.  Its "ass up" and canted up in the rear.

I also cannot use the iron site on the plate itself with a Holosun 403R.  I don't mind this but...yeah.

Lastly, the mount does not feel rock solid.  It will bend laterally if I put enough pressure on it.

It holds zero but I'm kinda bummed that I spent 75 bucks on this and its less than ideal.

Just an update, I have about 800 rounds down range across 4 different range sessions since I installed the Arterro "B" model with a Sig Romeo 5 on my Gen 3 PSA rifle and it is holding its zero just fine so far.  No real interference with the dust cover coming off and back on either.  I was able to adjust my front sight to co-witness zero correctly with the notch sight on the Arterro.

Bought a bravo mount for a Draco. Dust cover does barely go back on with the mount in place.

It had side to side play where the roll pin inserts.

I trimmed off part of an altoids tin, epoxying it on the front of the mount like a hot dog bun, poked holes in it for the roll pin to pass through, then installed as normal.  

Now it is snug side to side, if there is still movement it should affect the reticle less than the width of the front sight post but hopefully it will be solid, will zero then knock the optic left / right and see if it moves POI.