I have a Tatco. At the time of purchase, the Cleveland Main squeeze had just been introduced. It certainly does AD4 size rivets very easily and I came close to buying it. In order to do that, the handle travel has to be increased to get the mechanical advantage and that is a problem in some areas. It is not needed for AD3s which are the vast majority of rivets on an RV.
My recommendation is Tatco with as many different jaws as you can afford and include the quick change pins.
I have the "standard" jaw (1.5" deep I think), a DEEP one (3.5"?), a No Hole, and a longeron (tall, not deep).
As already stated in previous posts, it will squeeze AD4s but it takes a real grip.
About halfway through the build, I bought a couple of big (in diameter and length) hardware bolts that fit snug in the handles as "extensions". It makes AD4s much easier but you can put a heck of a load on the jaws so be careful. At that point it has the mech advantage of the Main Squeeze and also a similar (but different) problem in regards to space requirements for the handles.
Here's an example of innovation that is in many builders future (not this one exactly). I overlooked a pair of rivets and found then late in the build. There was no space for a gun/buck and the squeezer would not reach. And I was still being stubborn about wanting a solid rivet instead of copping out and using a pop rivet.
The parallel jaw clamp was a damaged piece of hardware in my junk pile. This pic shows the longeron yoke
