There is one feature can end up being a drawback on devices with limited storage. Right now, even if you install just Core, all the files needed for the Pro features are also installed. They may be compressed, I don't know, but they are there waiting to be enabled. This lets you use the Add Features to upgrade to Pro without having to supply any install media. The extra features just get installed or unlocked. This will make the basic install footprint bigger than it normally would be for a Core Install. Which is what most OEM PC's likely ship with. Mu guess is Windows 9's footprint will be even bigger. Just a guess at this point though.