30psi must feel awful tubed or not (even for a big fella.) I can't imagine, must feel like bouncing down the trail... not riding it. IMO too many folks mistakenly think soft tires slows them down when in reality it lets your tire roll things as opposed to bouncing off AND you gain stupid amounts of traction.
Me? Toobless 2.4 Ardents on a 29'er FS: 20-22psi rear/18-20 front. This is for around 175# geared.