This is the one you want.
The feel of the stock X-M1 gives you the sense that the engineers were focused on size/weight reduction rather than secure grip in the human hand. I knew it needed some grip enhancement.
First I contemplated a less-expensive PU-leather case, but these feature awkward tripod fittings and the need to remove the case to change battery/card. And some of them look like they might interfere with the operation of the tilting LCD. Then I contemplated a few of the more-expensive aftermarket leather cases with an 'escape hatch' for batteries, etc..., but the leather seemed too thin to actually enhance the grip of the camera significantly. Ultimately, I decided that the OEM offering from Fuji looked just right.
I'm so glad I did. Despite the concerns raised by another reviewer, this case does not in any way interfere with the operation of camera buttons on the X-M1. Either they received a defective case or they are using it on the wrong model of camera. Nor does it complicate extracting the battery or memory card in any way.
The leather is, as they suggested, of superior quality and it greatly enhances the handholding experience of the camera. Prior to putting this on, I never understood the location of the thumb-rest on the camera. Mine naturally gravitated towards the top of the LCD next to the hot-shoe. Now that I have installed this case, my thumb comfortably rests where Fuji wanted it do. One-handed shots are now very comfortable with the lighter lenses. With my heaver zoom it is still possible, though a bit of a strain. Regardless, it makes me want to hold your camera more, and that is almost priceless.
BONUS! It isn't mentioned anywhere, but mine also came with a genuine leather camera strap to replace the nylon strap that came with the original camera. It is of much better quality than the original, and I definitely plan on keeping it on the camera.