Of the many MacBook cases we’ve been playing with over the past few months, two have stood out as especially cool, but also especially nichey—in other words, if they fit a specific need that you have, you’re going to be thrilled, but if you’re looking for something typical, you’ll find them to be completely bonkers. The cases in question are Speck’s CorePack and Vaja’s new iVolution Shell, covered in earlier…