Whatever happened to a decent quality tire, tube and keeping them properly inflated and checking them every so often for any issues? Flats happen, to me not so much but I keep my tires properly inflated and try not to ride like an idiot on bad roads and avoid potholes and visible stuff when I can. You don't need goops or heavy liners which can cause more flats or at least lumpy tires or anything of that nature.

I dig the idea of tubeless but it can be a touch of a hassle not by much and the gap is certainly lessening with new technology coming out. One of my future bikes is probably going to be tubeless though I really love my Challenge tires and might have a hard time giving those up.