I tried super-light tubes a long time ago (Continental Supersonic and the Tioga one), but ditched them after consistently getting weird "scuff mark" punctures. This was back when I was still addicted to 20mm tyres pumped up to 150psi, but I'm not sure how much difference that made. In my opinion, they're not worth it. I mean, the Continental Supersonics are about 53g, and a regular 'performance' tube is anywhere from 90g to 110g, so there's a lot of rubber missing from the light tubes. The Tiogas were about 70g.
Yep, i continued getting flats (at least 3 a week) that were small scuff marks, in the middle of which were teeny pinholes. I asked about it on a forum a long time ago, and got this reply:
"Very thin tubes make great demands on the rubber sheet, and sometimes you get a tube with those scuff marks. Scuffs 0.005" deep on an uninflated tube can propagate into pinholes at 150psi when the tube thickness starts out about 0.050" and goes to 0.025" thick at 150psi. I had a ~0.075" thick tube that had large numbers of tiny (3mm) scratches that looked like Nike swooshes, and I finally tossed it after the 7th patch. The damn thing would hold air all nite then go down 20miles into a ride, always at a new site. Stick with 90-120gram tubes and avoid the misery. Steve"