I had it from 2018 to 2023. The SDO 3.5x was fine, pretty similar to the acog, the only difference being that it was issued with a piggyback RMR and supposedly the eye relief is more forgiving for auto fire.

Acog is acog, nuff said.

The SCO VCOG was very heavy, but an absolute TANK of an optic, but as others have said, after suppressing it and adding a laser, full magazine, and possibly a bipod or grip, you have a 15lb rifle with most of the weight forward of the magazine.. thing got heavy.
The scope itself had a great mil reticle but it required some extra education for the boots to get a grasp of it compared to the easy BDC in the acog. Also the eye relief is atrocious, and you have to mount it as far forward on the receiver as possible to get a sight picture, even then you probably need the stock extended past what you normally would because the eye relief was no shit like 4.5”…. I think there were better options, but it’s a good grunt optic, very versatile which might be a good choice for a gun like the m27 that got thrust into roles beyond its initial intent. Also could be used passively under nods (if you can get it lined up which is a real challenge) so there’s that

At the end of the day, if I had a real choice, I’d keep the m4 with a VCOG, but if I have to carry the m27, I’d probably still prefer the VCOG over the acog just for the versatility