I live off-grid. I have a MacBook Pro 17" (model A1261) which requires a 85W power supply. I also have a Solar Gorilla and a Power Gorilla which I used for a summer before I got the main solar system up and working.
You can't run the laptop directly off the Solar Gorilla because the power supply is too variable. There's a massive difference in what a panel can output in full sun and what happens when clouds pass over. The idea is to charge a battery (ie. the Power Gorilla) with the panel and then use the battery to run/charge your devices. The best use of the combo I found was to remove the laptop's battery and run the computer directly off the Power Gorilla. It doesn't draw a constant 85W and the bulk of the draw is for battery charging, so avoid processor-intensive operations and you can get a reasonable amount of time out of it. And I did shell out for the 3rd party MagSafe connector Solar Gorilla supply.