When I was initially shown this carabiner, I was just as confused as most are. However, after using it I will probably never use a different 'biner with a Grigri again.
*Note: despite what a different review states, this was designed to be used with a Grigri or devices with a similar design where the brake rope is wrapped over the right side of the device while lowering; this device is not compatible (specifically the friction horn) with all belay devices.*
Anyone that has lowered a climber on a thinner rope, or outside where there isn't any added friction at the anchor, knows that even with a careful hand on the brake lever, lowering with a Grigri can require a hard grip on the brake side of the rope.
With this 'biner, the rope can be redirected with the horn on the side, adding friction so the belayer no longer needs to death grip the rope while lowering.
Additionally, the way the 'biner was designed practically eliminates the chance of the Grigri cross-loading, both while belaying a lead or top rope climber.
These two features sold me on the Freino, though it did take some practice to not pinch my hand while opening, and it is a bit heavier and wider than other 'biners.
That being said, to anyone that uses a Grigri, I can't recommend it enough.