I recently purchased a Speck clear case just in case I needed it for travelling. Here are some pics of a 13" with and without, plus weight information. This info is for the 2010 MBP 13.3".
The case doesn't add a lot of weight, under a pound, but it does push the MBP up to near 5.5 pounds in total. (And yes, there is a bit of sanding that will be required where the magsafe adapter is. Look at the 3rd pic down to see. The battery does get powered, but the adapter sticks out just a bit. It will require about 1-1.5 mm of shaving of a bit of the plastic. Very easy to do, but why Speck hasn't corrected this, I do not know.)
With and without cases (And before anyone asks, it's a Skin-it "carbon fibre" decal)
Side View:
Weight without case:
Weight with case on
The case doesn't add a lot of weight, under a pound, but it does push the MBP up to near 5.5 pounds in total. (And yes, there is a bit of sanding that will be required where the magsafe adapter is. Look at the 3rd pic down to see. The battery does get powered, but the adapter sticks out just a bit. It will require about 1-1.5 mm of shaving of a bit of the plastic. Very easy to do, but why Speck hasn't corrected this, I do not know.)
With and without cases (And before anyone asks, it's a Skin-it "carbon fibre" decal)
Side View:
Weight without case:
Weight with case on
