all these half-cases prized crazily right now, mebbe wait for the gariz one which usually sell for around $100... also the kenji one looks overpriced specially with that shoddy looking stitching, mebbe intentional for that authentic home-made look. but to me just looks like poor workmanship
here's another expensive half-case selling on ebay:
af trick... just gave it a quick try (nothing scientific) and seems to work alright, seems less hunting... but sometimes still got that delay in locking focus...
"The X-Pro 1 autofocus is surprisingly good at locking onto moving targets – humans, bicycles and cars can all be caught with relative ease. First, set the X-Pro on AF-S (NOT AF-C). The trick is to depress the shutter in one go – the camera may take 1/4 of a second to sort out the focus, but it feels like there is some sort of an algorithm that compensates for that 1/4 second (or however long focusing takes) and puts the plane of focus into the right position."