I have the base Retina with 16GB upgrade, 2.3/16/256. Running a clean install of Mountain Lion and I'm left with 86GB left. That includes 90GB of music and documents. I don't need them all on my MBP but still, now I'm worried a bit about storage. 86GB is a lot left, I know. But I'm just curious as to how many people are close to maxing out their 256GB.