I just got a 13.3 Macbook I'm looking at getting a sleeve, and looking at previous posts and using google I've narrowed it down to the following five sleeves and have questions on each. Waterfield: how protective is the neoprene compared to polyurethane cases like the rebound and zeroshock? I would at least opt for the flap here. How much do the D-rings add to the length and width of the sleeve? I'm thinking if I get the Waterfield of possibly blinging it all out (though the cost is a little scary), but worry about using it just as a sleeve in my backpack. Chromebags: Again, how protective is this bag compared to the polyurethane sleeves and does it fit the Macbook like a glove? Radtech Rebound: The zipper scares me a little even with the inside guard, has anyone had any problems with zipper scratches here Shinza Zero Shock 3: Does it fit the Macbook like a glove? Again, same question with the zipper. And how does it compare against the Radtech Rebound? MacCase: How does this compare in scratch and impact protectiveness with the above cases? It says the flap does not cover the whole laptop, how much of a gap is there? From what I understand, the Rebound, Waterfield, and MacCase all fit the MacBook like a glove.