I would like to have an extra charger/adapter for my MBA, and realize that most forum members write that using a higher rated charger/adapter (i.e. 60W or 85W) is supposed to be fine. The cost is about the same for the 45W, 60W, and 85W Apple MagSafe charger/adapters. The 45W is a little smaller, but they're not that different from each other in terms of size either. My question is for those who actually did have to buy another charger/adapter, if you went out and bought the 45W charger, which would be good ONLY for the MBAs, OR if you purchased a 60W or 85W charger/adapter which in theory should be good for charging MacBook Pros in addition to the MBA.