Buy the pro. I think the pro is a much better machine than the air. The air has the newer technology with the flash storage and memory, but the macbook pro is not a slouch compared. The macbook air is designed for basic tasks, but it should be noted it can run more complexed tasks just very slowly. The pro allows for upgrades as well. But to answer your question about is 128 GB enough I would say no. For one you will always have to monitor your storage and space. Unless you buy an external drive to link up with your macbook air, you will have to acknowledge the limitations of the hardware on the macbook air. The macbook pro comes with a 250gb (Might be more now) hard drive, and the ability to modify RAM. The Macbook Pro also has better CPU speed when compared with the air, and processor speed makes a huge difference when a computer performs multiple tasks. So if you want a computer that will last for a while that is upgradable to a certain extent, get a pro. Airs look nice and the lightweight argument is valid, but I do not find it to be a good selling point.