Search:

A detachable magazine is probably of no benefit for culling mobs of goats etc if you only have one magazine - you can probably reload a floorplate just as quick as a detachable magazine.
The benefit...

I much prefer the floorplate option - more comfortable to carry the rifle in my hand.
A flush fitting detachable mag would be second place.
The only rifles I have/had with detachable magazines that...