I use them. Not often but then again, I don't need to use them often! I use the original big, round one on filters and the smaller rounded triangular one (called a SensorKlear) on my sensors (when a self clean and a blow doesn't do the job). Both work very well and keep their places in my bag. I treat the SensorKlears as a one shot solution - after their use as a sensor cleaner, they get relegated to use on less delicate things (or at least less critical things) like rear/top screens, viewfinders, 'phone/iPod screens etc. I bought several from 7dayshop a few years ago and still have a couple of virginal ones left - they were on special offer so very cheap, hence the one-shot being not too expensive.