[bobstro]

The problem under KitKat is that, without workarounds, most apps can't write or delete files on removable storage that belong to other apps. Each app is allocated a private area it can use. This means things like 3rd party file managers can't be used to delete ebook files on uSD, nor can I use sync apps that write and delete files on uSD. The biggest frustration to me was not being able to use Calibre Companion to manage my ebook collection on uSD.

Authorized system apps such as Samsung's file manager CAN access all files, so hopefully, Google will provide some means of allowing the user to authorize certain apps to do things the old way. In the meantime, I have to more-or-less copy stuff over manually and use the Samsung file manager for pruning. For the time being, I've gone back to plugging my tablet into my Calibre computer and managing the collection over USB. A definite step backwards.

The other problem is that, although apps can read/write to their own private storage space on uSD, most apps don't. They dump files into your internal storage. I found this a problem even on a 16 GB device and had to modify how I used it. Again, apps may be modified/improved over time to address this, but Google isn't pushing them to do so. Some apps do support moving app data to removable storage, but this varies by app. Unfortunately, this means the answer is "it depends" based on your particular selection of apps.

For now, just consider removable storage to be a place where you can dump files to be read by apps. It's fine for things like movies and ebooks that can be read, but not managed, by apps you install. I still much prefer to have removable storage than not, but it's not as useful as it was before KitKat. I certainly didn't need to pop for a 64 GB card right before installing the KitKat update!

I'd advise buying as much internal storage as you can possibly afford, with an eye towards adding a smaller uSD card later if needed.