I've been on the search for my first defense of shotgun but am having difficulty narrowing my choice between semi auto or pump. My dilemma is rate of fire (speed) versus capacity.

Now a choice between a high-quality semi auto or the old standbys (Mosberg 500 / Remington 870) is a easy choice for me-I'll go with the high-quality semi auto (Benelli M4, M2, Beretta 1301, Remington Versa Max, FNH SLP, etc.).

The defensive shotgun(s) that have me questioning the semi auto route are the duel tube modern bull-pup designs that hold 13+ 1 on board. (20+ With mini shells). I've been looking seriously at the Keltec KSG. 18 inch barrel in a 26 inch package with a 14 Shell capacity is pretty attractive option. Reloading is obviously a slower proposition than a standard pump...but 14 shells.....

So I'm curious to hear from members who use and train with defensive shotguns. When it comes to these types of weapons, what's most important to you between these two features; rate of fire or capacity? (Let's all agree that reliability is of the most importance). Would love to hear firsthand experience-pros/cons of the platforms I've listed above - and general opinions with rationale behind my primary question.