I've had them on my road bike with compass 700x28 tires for almost a year now.
You can patch them if you get the patch kit made for them. (sold separately
) I have the kit though I've not had to use it because I haven't had a flat yet. They seem tougher than latex and don't leak down quickly like latex does, which is nice.
"
permanently stretches to the specific width of your tire" should only be an issue if you take it out and try to install it in a narrower tire.
Besides the weight savings the Tublito is much more compact then a standard tube when new, allowing for a smaller size flat kit.
The plastic valve stem is the weak point. While detaching my clamp on pump head the plastic split and the metal valve core blew out. No way to fix, but Tublito did send me a new tube free of charge. Now I'm more careful and have not had this issue again. If you use a pump head that screws on, it may also unscrew the valve core when you remove it. After this happened to me on a new tube I epoxied it back in so it's not coming out.
Both of my issues happened when new. Since then they've been issue free. Unless I start having problems with them I'll likely continue to use 'em.