Tom Bihn's Ristretto vertical messenger bag for tablets or laptops up to 13 inches (which makes it perfect for 12-inch MacBooks, MacBook Airs, 13-inch MacBook Pros, and iPad Pros) is, at US$140, not an inexpensive purchase. But if you've got the moolah, it's well worth it.
The Ristretto has a built-in interior padded compartment (12.8 x 9 x 1 inches) that protects your iOS or OS X device The padded compartment is made with 25-inch open-cell foam laminated with four-ply Taslan on the outside, and features an interior of soft brushed nylon. The back side of the Ristretto is padded with 1/4-inch closed cell foam.
The Ristretto is available in verde/steel, steel/liberian/ and black/steel flavors. You can also choose from two shoulder straps (Standard and Absolute) that attach to snaphooks via d-rings. The Ristretto comes with the Standard strap, but the Absolute is an extra 20 bucks.
With all these features, the messenger bag offers some serious protection for your iPad or Mac laptop and it looks good, too. For us guys, its rugged appearance will ward off any "man-purse" jokes.
Speaking of man-purses, I don't think the Ristretto can hold as much stuff as my wife crams into her purse (she has more items in it than Santa has toys in his bag). However, you can get a surprising amount of goodies in the the messenger bag.
Four hand-sewn pockets offer room for small items like pens, cell phones and the like. There's also a zippered pocket, where you can stash things such as your billfold. There's a bigger-still compartment (in which you can squeeze -- if you squeeze really hard -- an Apple Bluetooth keyboard). The main compartment uses a simple flap that folds over the top of your iPad without Velcro, zippers, snaps or magnets.
Tom Bihn offers a magazine/newspaper pocket sewn to the back of the bag. Three O-rings attached to the two main compartments and a fourth inside the zippered pocket. These hold organizer pouches, which come in various sizes and can be clipped to the O-rings. I use one to keep my headphones and a cleaning cloth handy. You can order extra organizer pouches with pricing starting at $7. Tom Bihn also offers a $2 key strap.
If you need a waterproof case, you'll need to look elsewhere. The Ristretto isn't waterproof, but Tom Bihn bags are coated on both sides for water resistance. Also note that the Tom Bihn case won't accommodate an iPad in a thicker case.
Otherwise, if you need a tough, attractive iPad bag with lots of bells and whistles and plenty of options, the Ristretto is your baby.