The Revel sleeps three comfortably is what we understand.
I'd check out a Revel in person with this specific question in mind before you commit.
We're a family of three and were initially excited by the Revel, but we found the implementation of the third berth to be lacking.
Basically the third person sleeps East/West from the dinette across to a flip down extension that comes off the cabinet by the side door. The net effect is that nobody can use the side door while that bed is deployed. As the early riser in the group, this was a bummer of a Revel-ation, since it means either I'm trapped until kiddo is awake and I can store the bunk, or that I'm relegated to the third bunk and the kiddo sleeps with my wife.
Given that "family of three" is our normal operating mode and not the occasional condition, I'm constantly shocked and surprised at how few van layouts support even 1 more person, given the overall large size these days.
(For comparison, our tiny Astro with a modified Westy-style layout sleeps 3 or 4 with unobstructed access to the doors, room for a stowable porta potty, and some rudimentary cooking facilities)