I spent a year with tubelss (or maybe less, I can't remember exactly) before I quit...for me, they were way more trouble than they were worth. Maybe the ones I had were just crappy ones (they were Mavic, that came with a wheel set) but in that year i destroyed THREE of them.
The lower pressure was softer, but no big deal. Since I went back to tubes, I've never once thought of going tubless again.