Depends what you want a shotgun for. Do you wanna hunt ducks, shoot skeet or blow extremely large holes in bad people?

To a certain extent semi autos have less recoil. They also cost more. There is the potential for less reliability. The theory is that pump shotguns are good for defensive purposes because they will not jam and are considered extrememly reliable. Of course if you clean and maintain your semi-auto properly it should always function.

It is possible to short stroke a pump shotgun. This is unusual and I still think that pump guns are the way to go for absolute reliability. Short stroking involves not pumping the action all the way forward and all the way back so the fired shell is not cleanly ejected while the next shell is popped out to be put into the chamber. I have never done this in my life and have fired 1000's of shotgun shells. However my friend, who has hunted with me for years, short stroked his shotgun while firing at a deer. I actually saw him do it-what a mess.

Remington 870s are most people's choice for a pump gun (I love mine ). There a billions of 'em so there are lots of parts if you want to add something or need a part (not likely).

I don't like mossberg pumps 'cause the pump grip kind of feels loose on some of them, but they work fine and are cheaper than Remingtons.

I like the looks of the Fulton Armory FN Police Shotgun www.fulton-armory.com/ but have never gotten a chance to play with one.

Benellis are wonderful shotguns. That Super Black Eagle pictured above is sweeeet. I still think a pump is the way to go for a defensive gun, but I have never had a failure to function on a Benelli. If you are getting a semiauto that'd be a great gun. A semi auto does fire a litte faster than a pump, but I don't think it's a significant difference.

I guess there could be some oddball situation where being able to fire a semi one handed would come up, maybe opening a door??

I don't remember having fired a Franchi.

I saw a semi-auto fighting shotgun with an H & K label Friday, I think they are made by Fabarms for H & K, certainly looked bad ass.
---
I don't think the pistol grip is worth it, but you might like 'em, try it and see.

I THINK those "convertible" pump/semi guns are intended for police use because some of the fancy police loads-non lethal/gas/door busters-won't cycle the action 'cause there isn't enough powder in 'em. I wouldn't bother with one unless you really fall in love with it when you try one.