The Fuji X100 leather case is a very nicely made item, with a good, grippy stylish brown leather shoulder strap which replaces the standard one provided with the camera. It has subtle logos pressed into the top of the case and the strap. It is pretty much required to have a strap fitted when using the case, as the popper straps which secure the camera into the bottom half of the case wrap over the strap rings. In a pinch, you could get away with having the rings fitted but not the strap.
There is no tripod screw to hold it into the case, and no hole which can be used to secure the camera onto a tripod with the case fitted. The top half of the case including the leather lens cover attaches to the lower half by a pair of poppers and can be removed easily, though it doesn't fold up particularly conveniently for storage, so you may be better off just letting it hang below the camera in use as it is designed to do. It doesn't really get in the way, anyway.
With its tough experior and velvety interior, the case provides good scratchproofing and a certain amount of impact protection. It may also be useful to repel the odd light shower of water, though it's clearly not designed to be waterproof.
The catch which holds the top cover closed is magnetic, and has an amount of play forwards and backwards. What this means is that you can install the filter adapter and a reasonably slim filter (I use the excellent B+W 007 Clear MRC) and still use the case effectively, as the leather lens cover will slide a few millimeters forwards and still fasten securely. There is no way that you can close the cover over the camera with the optional lens hood fitted however, so you'll need to carry that in your pocket when not in use. Luckily it attaches and detaches with ease, and is very pocketable.