Yan 

That's quoting a higher end cassette here. SRAM also sells the lower end PG-1230 and budget PG-1210 cassettes for those who prefer to spend less. These have the additional benefit of using the old regular Shimano HG cassette body, so they'll work on any wheel you already have. They do weigh a bit more.

Is 1x trying to solve a problem that doesn't exist? Maybe. The benefits are no more having to do double shifts, no dropped chains, and maintenance simplicity. Admittedly these are pretty marginal benefits. Then on the flip side, the criticisms are the lack of overall range and larger gaps between gears.

In my opinion neither of these criticisms are applicable to touring bikes. Set your chainring size so your minimum speed is 4 mph. Below that you can't balance anyway. You have the same low gear as any traditional 3x bike. Now your top gear is limited to 20 mph. 4-20 mph, you have 12 gears within an operating speed range of 16 mph. You almost have one gear for each 1 mph. How much more granularity do you need? Let's be serious.

Now someone says 20 mph is too slow a gear for them. You're on a touring bike. Your panniers are sails. 20 mph is a century in 5 hours, a proud feat even for someone on an aero road bike. You're not doing 20 mph on your touring bike, sorry, no offense. If you are doing 20 mph, it means you have some outside aid like a down hill or a tail wind. If you have an outside aid that is already giving you freaking 20 mph, how much faster do you need to go? You're already at the speed where you do a century in 5 hours. Holy sh*t how many miles do you want to tour in a day???? Just rest your legs and chill.