Love these tubes! Yes. You can feel the difference. Just a nicer feel than butyl tubes. And they have less rolling resistance. They loose air pressure more quickly, but they are NOT more delicate or more puncture prone than standard butyl tubes.
Boy these are heavy tubes. But after three consecutive days of flatting from different punctures on new tires, I gave up. Once installed, your wheels will noticeably slump around and handling is pretty terrible. But hey, no flats after 600 miles so far, a couple self-healed punctures, and they hold air like a dream. I'd never use them for training or weekend rides, but they serve their purpose for daily commuting peace of mind.
I'm not aware of any reputable objective report that shows that one brand of butyl tube is better than others, so I don't see the need to pay more. Mine have worked fine as tubes go (including the ones with the name Kenda printed on the tube but with a different name on the box), which is to say, they will puncture when pierced by sharp objects, like all tubes.