When changing strings on one of my Suhr's last week I decided to set it up in all fourths. I've only played that guitar since then and I quite like it. The symmetry makes improvisation noticeably easier.
So far the only down side I've noticed is that bar chords are either impossible to play or real finger twisters. Frankly, I don't care about bar chords, so this isn't much of a problem.
Has anyone else played in all fourths?
I've tried it out before. I thought it was good for lead, solos, and all that single notes stuff, but not very good at all for chords. Without the major third interval, it makes a lot of chords difficult to fret (many impossible to fret).