Serious trade-offs and malfunctions. - Viridian Weapon Technologies S&W Bodyguard 2.0 RFX-1 Custom 1x16mm Reflex Red Dot Sight

I am hesitant to give products 1-star reviews because most of them have things they do well. In this case, the product has too many trade-offs combined with poor performance and bad quality.

Trade-offs: Battery below the optic (requires removing the optic to change the battery). Automatic brightness adjustment (no manual buttons).
Those would all be fine if the optic performed. You trade those features for a smaller profile.

Performance issues: In low light, the dot is too dim to see it. It's EXTREMELY dim. If you're in a dark room/hallway and looking into a lit area, you will not be able to find the dot. You'll end up using the optic sides to "frame" the target.

Malfunctions: At the range, the default dot setting was crazy high in the window. This required me to dial the elevation adjustment to the end of its range in order to get it on target. The problem is that it didn't stay there. I had the same problem with windage. No matter how I adjusted it, the adjustments WOULD NOT group in the same spot. Just to make sure I wasn't crazy, I brought out my EDC and competition gun. Both Holosuns were on target and grouped fine.

You're giving up a lot in order to get the smaller form factor, but if it can't hold zero, none of that matters. Time to try the Gideon Pebble.