I'm lucky to have a Performance Bicycle shop a couple blocks from where I work so I've started using their Forte brand tubes in all of our family bikes. I've yet to have a single issue with either Presta or Schrader valved tubes in both road and MTB sizes. They don't seem to lose air any faster than any other brand I've used, and we've yet to encounter a flat that could be attributed to the tube as a fault. So, the price is right, they always have the sizes I need, and their point club points add up to some nice discounts over time.