After plenty of digging I was unable to find an answer to this question. Hopefully someone here will be able to offer some insight. I've been successfully using the BookArc with insert #7 for my rMBP. I recently picked up the Speck SeeThru Satin case and love it. With the case on the laptop is too big for the rMBP insert (#7). It will fit in the cMBP insert (#5) but it isn't nearly as snug as the naked MacBook fits in insert #7. My guess is that the laptop will be fine like this but I wanted to see if anyone else was running theirs like this? Has anyone else run into this? Thanks!