I would go for the 256GB if the price difference is $100, but I think the price difference is $200. I think $200 is way too much for 128GB of extra storage unless you need it to install lots of programs. With 128GB, you already have about 95GB left for programs. If you need extra storage for data like pictures/movies, just get a 128GB USB flash drive for like $35-$40. Or if you get the 13" one with SDXC slot, you could get a 256GB SDXC card for like $100.