I used to just chuck mine in the pannier, but then one day the pannier bounced off and the laptop case cracked around the fan vent. So I went out and bought the REI commuter pannier and an REI e-sleeve. I think the main benefit is that there's no room for the laptop to move around, and this pannier hasn't come loose. The e-sleeve has a lot of padding, but I'm not sure how much it would actually help in a drop.