I own both a Tom Bihn backpack (Brain Bag) and the padded laptop compartment (Brain Cell): I assume this is the exact arrangement you want to compare against. I have many other assorted bags, etc., including padded ones from Mountain Equipment Coop (MEC), which is practically the most famous independent maker and distributor of bags, outdoor equipment, etc. in Canada.
The Tom Bihn arrangement of backpack + laptop compartment is the MOST EFFECTIVE you can get in terms of protection. The Brain Cell is made of what appears to be corrugated plastic formed into a box shape. The inside is covered with a soft and rather durable feeling felt material. It is velcroed at the bottom, allowing you to 'cinch up' the bottom of the covering, forming a sling that your laptop is then suspended in. The top of the Brain Cell is also sealable. When you drop the Brain Cell, the force of the contact will be borne by the sides of the case first. Yes, there might still be some shaking; however, there will arguably much less direct transmission of force on the laptop edge itself than would be expected when the only thing to absorb the force is foam padding. A lot of cases don't have that much foam padding anyways. The 'suspension system' will also help dissipate the force. Assuming you drop it in the correct orientation, I estimate your laptop will handily survive a low level drop onto bare concrete. The corrugated sides also offer some actual rigid impact protection from sideways bangs and bumps, unlike neoprene (limited effectiveness) or other material you would only find in a slip case. Thus, you have additional protection if your backpack is tipped over, kicked as students move between rows, whacked into handrails or posts on the subway, bus, etc. Furthermore, the Brain Cell clips to the inside of your backpack (mine is an older model, so it snaps together). This is another advantage. Just a like a seatbelt in a car holds the person to the vehicle in an accident, you want the laptop to stop moving when your backpack hits the ground, otherwise the backpack hits and stops, and then your laptop, if it's in a sleeve that is too small for the backpack, will continue in motion and then also hit, bounce around, etc. The Brain Cell and Brain Bag become more-or-less as 'one' (very spirtual here...)
The only disadvantage is the Brain Cell is a bit squarish and bulky. There's no denying it's in your backpack when the whole thing is on your back. So, if I'm not in a situation where I think I will be bashing the laptop around, I use a less protective sleeve for my laptop before sliding it into my Brain Bag.
Unlike the poster whose TB Messenger bag fell apart, I have had my TB Brain Bag for six years. I didn't use it when I was a student, but for the last five, I've used it almost every day as a professor. It has carted everything from heavy textbooks, lunch, gym shoes, 3 different laptops, etc., and sometimes dangling off of one shoulder. It is very roomy, and even better, there are two compartments. Not one stitch has yet to rip. I have an older model and I got it in black (good for business day trips): it looks pretty the same as when I got it, although admittedly a bit more worn. The black has not faded however. I also bought the TB Snake Charmer to hold cables - very nice.
You will be able to fit into your Brain Bag approximately:
First Compartment
- Brain Cell with laptop; and
- Snake Charmer OR small rolled up item on top of Brain Cell (e.g., sweater, small packed lunch); and
- Some thin files, thin reference book, or clipboard BETWEEN the Brain Cell and the dividing wall of the Bag (the Cell is stiff so it can help keep papers neat and uncrumpled).
Second Compartment
- At least two thick textbooks (three if you really stuff it); and
- A thin binder; and
- Lunch on top of the textbooks; and
- Some odds and ends in and around the books, like a paperback for down times.
- You could probably stuff gym clothes and MAYBE running shoes if you're not hauling too many books around.
... and you still have the outer pockets for a water bottle, iPod, sunglasses, keys, gum, umbrella, calculator, pocket camera, etc.
BUT keep in mind this will weigh you down, so watch your back.
The Brain Bag isn't perfect: it can 'bulk up' when you fill it up, and it doesn't have an ergonomic back like some of the newer backpacks (e.g., Booq). However, it has 4 GOOD compression straps, a waist strap, a sternum strap, and some wicked pockets, as well as an umbrella holder/straps. Compression straps are critical to holding the load closer to your back and therefore your centre (oops, Canadian spelling there) of gravity; and a chest or sternum strap is essential for preventing a heavy load from dragging your shoulder straps outwards and downwards off your shoulders and onto your upper arms. The carry handle is nicely designed and easy to hold, unlike the plastic/rubber grip ones you find more commonly these days.
And... my wife and I bought two Tom Bihn Aeronaughts for carry on travel luggage. Very, very nice... and in my opinion after trying half a dozen bags, the ultimate carry on case that finally gets it right.
Good luck.
