Replacing the screen of the Surface ProI, and others I know of, bought the 64GB Pro with the intention of upgrading it (in my case, I had no choice. I needed a new ...
Answer to: If you buy the 128gb Surface, will it perform better?Yes, write speeds should be faster. However, don't expect to notice any obvious difference in everyday usage. The vast majority of writes are small and take little time compared to reads. Unless you're the person who frequently writes large amounts of data (and I mean LARGE), odds are you won't notice a thing.