The Zip Sleeve for the BlackBerry PlayBook I can honestly say is my favorite case to date. I picked up this orange one at BlackBerry World (unfortunately we don't stock it, but we do have blue, black and gray) and I have been using it ever since. I did start out with the convertible case, but I've since moved on as I prefer the "naked" device without having it in the case all the time. The zip sleeve keeps my PlayBook protected all the time, and it's easy to get it out and in again. If you're somewhere that you need to get the tablet in and out of the case quickly, you can also leave it half zipped so it acts like a slip case of sorts. Overall I highly recommend this case. It does what I need it to and it holds up to the elements. Check out the video above for my quick review.
More info / purchase of the BlackBerry Zip Sleeve