icemilkcoffee 

That looks like a long awkward reach-around for your thumb. Also, when the right shifter looks to be right in front of the brake lever. You'd have to reach down pretty low to avoid the shifter if you want to brake.

Andy_K 

The shifting motion has become pretty much second nature to me now, so I may not even be doing it the way I think I'm doing it, but I think I do most of the shifting with my fingers. I might use my thumbs when the lever is in the far inward position, but usually I think it's my fingers.

When the shift lever is sticking out to the left of the brake lever it is a little bit in the way. Generally, I just keep my index finger off the lever in that case and brake with my other three fingers in the usual position. It's not as bad as you might think.

One thing that should be said is that these levers are purposely designed for cyclocross use, and that's where they really shine. When you're charging down a hill in a big gear and then need to do a 180 and go back up the same hill it's very nice to be able to sweep through your whole cassette in one motion. Also, when you slide out in a muddy corner and bash your shifter into the asphalt, it's great to have a mechanically simple solution. The pic below shows the result of me doing exactly that.



I think the simplicity and the durability translate pretty well for gravel, randonneuring, and touring. For general road riding, more traditional brifters may be preferable.

Check out this video, which shows the shifting motion and also mentions the things I said about why they're great from CX: https://vimeo.com/94598775