Practically any Aimpoint coupled with the right sized mount.

I use a T1 on a FAST riser with very good results

Concur.

As others have alluded to, the EOTech provides the best light transmission of any RDS I've tried so far, due to both the holographic technology used, which does not require the same types of lens coatings as projected LED dots, and bears more resemblance to a fighter aircraft's HUD than most other red dot sights available on the market.

Moreover, both the housing size and shape translate to better light transmission as well as field of view--not only is the EOTech's housing and protective outer hood thin, and designed to allow some light to pass through, the rectangular shape (as opposed to circular) means that more light can get "past" the optic housing due to asymmetry between the image intensifier's field of view and the optic. A circular FOV essentially creates a concentric "blockage" that ultimately prevents more light from reaching the image intensifier's objective lens, leading to a darker overall image--even if the optic housing is only "seen" as a blur or shadow, it is still blocking valuable light from reaching the user when placed between the target and shooter.

Night vision compatible EOTechs also not only have the convenient "NV" button that allows you to immediately switch between daylight brightness and passive NV use, but the buttons also "remember" the brightness settings, meaning you don't have to cycle through to find the "right" setting as much as you would on a rheostat dial.

Moreover, the NV-compatible EOTechs have ten brightness settings for NV use, as opposed to the 2-4 that are common on most other dot optics, allowing you to more precisely dial the brightness for your environment and intended use. Having shot passive for quite a while, depending on environment and conditions, I've needed to dial the brightness back to the "bottom" of the NV settings in extremely dark conditions, to actually needing to go into lower visible settings in brighter environments.

Our daylight optics often have 8-12 daylight brightness settings based on variability of conditions, I see no reason why our NV optics should not also. Four is less than ideal, and two pretty much only works for pistol applications.

Different optics have their own advantages and disadvantages, and I use a lot of other optics, including for passive NV use, including T1s and T2s depending on what my particular needs are for that rifle--I am far from saying that the EOTech is the only serviceable optic for passive aiming use.

However, if performance and capabilities for passive NV shooting are the sole consideration, EOTechs are still the best I've used by a wide margin.

~Augee

EOTech only ever made a lower-1/3 cowitness variant way back in the day with the 553 SU-231/PEQ due to a USSOCOM requirement. The EXPS3-0 is the commercial version of the SU-231A/PEQ so naturally it matches the height, and EOTech introduced the lower-1/3 height in some of their other models, most of which were nowhere near as popular and/or now discontinued like the 555.

Moreover, the nominal ~1/4" height increase from absolute cowitness (1.4"-1.54" for most manufacturers) to lower-1/3 (7mm or 0.276" for EOTech) is lower than a practical riser height to have enough room for the Picatinny rail and some sort of clamping/attachment mechanism. This is why the LaRue LT110 riser design is so unusual and has the "hump" on the rear, as well as the set screw attachment method of the Wilcox .410" risers--1/2" is really the lowest you can go with a traditional riser setup, which is why they're so common, and which is why the mount had to be redesigned for the EOTech 553 relative to absolute cowitness EOTech models in order to achieve the lower-1/3 height.

Once you start going above lower-1/3" however, it's less of an issue. Lower-1/3 is still generally a de-facto "standard" for most of the AR shooting community, despite gains made by the taller optic crowd, especially in recent years, however those who have been on the "tall optics" train for a while have been using various risers for years such as ARMS, KAC, LaRue, etc., without issue--it's more cost effective if aftermarket risers are available to produce the "more commonly known" heights, and guys that want to go taller still have a plethora of options, rather than re-designing and producing a brand new optic housing/mounting base.

~Augee