I've mentioned this before, but a 2x rivet gun makes riveting the majority of an RV's rivets really easy.
A 3x gun of course works fine but you do need to bring the pressure down. And of course you need it for the larger diameter rivets.
A 2x gun on the 3-# sized rivets is a real joy to use.
It is worth the extra expense, but it is so unusual a purchase that when I ordered a 3x AND a 2x gun, Cleveland tools called to confirm I really wanted both!