The world of pistol optics is being steadily taken over by enclosed emitter optics. Aimpoint started the trend with the ACRO, and that category of optics continues to evolve and expand. Trijicon is promising to release a new enclosed red dot soon. SIG has made more than one now, and Steiner also jumped in on the action. Not to mention Holosun, Viridian, and others are embracing the enclosed emitter.
When it comes to defensive handguns, shooters like reliability and enclosed emitter optics max out the reliability factor. Two of the big names in this marketplace are the SIG ROMEO2 and the Steiner MPS. I have both, and honestly, I’ve become a fan of both. The question comes down to which is better. Both of these optics are high-quality, premium-grade options for defensive and competition firearms.
Why compare the two?
At the moment, SIG and Steiner are the two big names in the enclosed red dot market that are not the Aimpoint ACRO. The ACRO P-2 model is dominating the market. It’s popular enough that it’s often tough to get. Both the ROMEO2 and MPS tend to be easy to find. Both are full-sized red dot optics aimed at duty-sized handguns. They are both fantastic optics, but does one edge out the other?
The Big Difference
There is a huge difference between the two, and the biggest difference is the design of the ROMEO2. The ROMEO2 is an enclosed emitter optic when it wants to be. It’s modular and can be converted from an open emitter design to an enclosed emitter design. As far as I know, this is the only optic on the market that offers that degree of modularity.
The MPS delivers a standard enclosed emitter red dot. It’s not modular, and that’s fine. I’ll admit once I have the ROMEO2 set up as an enclosed emitter, I don’t have a plan to take the thing apart and swap to an open emitter. Does that modularity matter? That’s the big question. If so, then the optic delivers. If not, then well, then it’s up to you.
Mounting the Optics
The MPS uses the ACRO-type plate, which was a smart move. It’s useable and proven, and you can find the plates anywhere online for various mounts. You need a plate that can attach to your gun’s specific footprint. This means you might need a Trijicon RMR to ACRO plate or a Leupold DPP plate to ACRO adapter.
The MPS comes with a plate that mounts to Docter footprints. That’s an odd choice, admittedly, but the good news is that you can find a wide variety of plates to allow the gun to mount to various slide cuts. Additionally, you can have a slide milled for the ACRO footprint.
Whenever you use plates, you are tolerance stacking, so be sure to tighten them down to proper torque and use a thread locker.
The SIG ROMEO2 uses the SIG Pro cut. This is a slightly modified Leupold DPP footprint. From my understanding, the ROMEO2 can only attach to optics with the Pro cut. This makes it limited to mostly SIG pistols, and you’d require adapter plates elsewhere. One of the benefits of the modular design is that you can attach the ROMEO2 directly to a gun without a plate or fancy design and then slap the rear lens and top cover on.
Battery and Power!
The SIG ROMEO2 will last for 25,000 hours in a Medium setting. The MPS has a considerably lower 13,000-hour battery life at Medium setting. The ROMEO2 has a very aggressive MOTAC feature that shuts the optic off automatically when it remains still for several minutes. After it shuts off, the optic powers back up as soon as it detects movement. The MPS has an auto-shutoff feature too, but it doesn’t shut off until after 13 hours of no movement.
That’s silly. For many of us, this means the optic will never shut off. It’s unlikely I’ll be unarmed for the majority of the day, so it will always be turned on. Luckily you can turn the optic off manually very easily, and that’s what I suggest you do.
How do the ROMEO2 and Steiner MPS compare in size?
In terms of weight, they aren’t too far off. The Steiner is 2.05 ounces, and the ROMEO2 is 2.10 ounces. No noticeable difference. Both of these optics are fairly large, as enclosed emitted optics tend to be. The MPS is 1.25 inches wide, and the ROMEO2 is 1.32 inches wide. The MPS is 1.125 inches tall, but with the plate required, it’s about 1.25 inches high. The ROMEO2 is 1.12 inches high.
There is no big difference between the two until we come to the lens design. The Steiner MPS has a 20×16 mm-sized window. The ROMEO2 has a 30 mm-sized window. It’s a considerably larger window. Larger windows are easier to use for new red dot shooters, but the difference fades away when you get some experience.
Ergonomics
Ergonomics with a red dot really comes down to adjustment buttons and battery removal. Both score high. The Steiner MPS uses a top-mounted battery that makes swapping batteries quick and simple. The ROMEO2 uses a side-loading, spring-loaded battery. Just press the button, and the door pops open.
Button-wise, both place their adjustment buttons on one side of the optic. The Steiner MPS buttons are much larger than the ROMEO2 series, so they are a bit easier to press and adjust. The ROMEO2 buttons are smaller and recessed. The benefit of the smaller, more recessed buttons is that they are nearly impossible to be accidentally pressed when holstered. Both have benefits, and it’s really up to the end user.
Banging Hammers With the Optics
Clarity with both optics is high and very nice. The Steiner MPS is remarkably clear from front to rear with only a slight blue tint. The ROMEO2 can be just as clear, but it takes a little work. Installing the rear lens and top cover is easy, but if you do not ensure the area is dry and moisture-free, you can get some fog between the lenses. It takes a little extra work to get the optic to be as clear as possible.
Dot-wise, it’s tough to tell if one is better than the other. Both offer very clear dots. The ROMEO2 comes in three configurations: a 6 MOA dot, a 3 MOA dot, or a dot and circle. The Steiner MPS comes with a 3.3 MOA dot. Both are very clear. If I was forced to choose, I’d argue the MPS is a bit crisper and easier to see.
Both use 1 MOA adjustment, and both are easy to zero. They both provide tactile adjustments that click and pop with ease. I got both of them zeroed correctly at 25 yards with minimal issue.
At the range, both optics perform extremely well. They hold zero, they remain clear, and it’s easy to hit targets at various ranges. After hundreds of rounds through each and plenty of bang-arounds, drops, and terrible temperatures, they still work without issue. I’d argue that since the MPS is a one-piece design, it’s tougher, but that’s like the difference between 6061 and 7075 aluminum.
Which is Better?
The Steiner MPS is a good bit cheaper than the ROMEO2 and is a very competent optic, all around. However, the features of the ROMEO2 make it a better optic, in my opinion. It’s not perfect, and it can be more challenging to ensure total clarity, but it is a robust, feature-filled optic. This is my opinion, but what’s yours? Let us know below and Check out the ROMEO2 and Steiner MPS.
