I got this piece on a recommendation from a friend (he tried the Mesa Tactical Side Saddle first and was disappointed). The first thing I noticed was the extremely poor fit. The base plate sticks out above the top (and bottom) of the receiver of the shotgun, which to me looks ungainly and poorly thought out. The second thing is that the Side Saddle interferes with the stock forend. My forend is still 3/4" from being fully to the rear when it collides with the shell holder. It doesn't really interfere with function of the shotgun (I can still combat load and eject shells properly), but the constant impact of the shell holder and forend colliding beats the tar out of both. On the other hand, it hold shells securely. They're easy to grab, and easy to slide in and out. I just wish my shotgun didn't look like I tried to bolt 1986 Cougar fenders onto my 1969 MGB.
Pros: Shells slide in and out easily, durable and solid
Cons: Not designed for 20ga receiver, looks awkward
This review was written in the old system and had content requirements that are different than reviews written today.