been running these for a year now on one of my road bikes and had zero flats over about 5000km with 28mm Conti GP5000 while my other bike did flat twice.
they handle well and are indeed very light plus they work with valve extender in my 60mm wheels though i do have to pump them up every 2 weeks. They dont go completely flat but wont hold 90PSI for more than a week.
I think its a great product. i cant say they are better than latex as i never tried those. in combination with the gp5000 they can certainly handle rough terrain which impressed me!
the price discussion is funny: 30 USD? i spend more on bars and electrolytes each month and been running this tube for over a year so i think its good value for money if they last this long 