I needed to find a good quality tube for my hauling bike. After a few weeks of use on the roads, I not once had to break out the tire repair tools! ) (New rim tape also helps.) I did add some air but with weather expansion-contraction, that's normal. Very pleased.
I bought the Continental 1.752.5 MTB 26 tubes with the Presta valves to install with my Michelin Country Rock 26 1.75 tires that I bought at WesternBikeWorks. I store my bike in my home, but I haven't had to add air in the tires for 3 weeks and the pressure is still the same. With my old tubes, I had to add air weekly. These tubes have exceeded my expectations. Will buy again!
The 25-32 size is really handy because it covers the sizes most commonly used on road and gravel. The 60mm length is perfect for the slightly aero rims I have, no need to mess with extenders and moving valve cores.