I love the one page idea. If you can't spend the time to articulate a page worth of constraints, you're going to flail around discovering them as you go. And these aren't "bugs", they're "oh shit we're building the wrong thing" flaws.

I have no hard data to back it up, but in my experience, projects that take the time to put everyone on the same page conceptually (even if it's a 1 pager, high level, here's what we are and are not doing) end up succeeding far more often than projects that wing it. The wing it projects always end up disappointing everyone who had opinions but never bothered to articulate them.