That SanDisk is compatible.
This whole available storage thing, while upsetting, is not really something you're unfamiliar with.
Pretty sure that we've all bought a PC.
With an xyz GB hard drive.
Hardware and software think in powers of two. A gigabyte is 2^20, but in the world of marketing, a gigabyte is now 1 billion. So all hard drive GB numbers are a lie.
Then comes formatting loss. The xyz GB number gets its second lie.
Then comes Windows and maybe Office pre-installed.
And that uses up more of your xyz GB.
And no one complains that's an unfair practice.
This is no different.
The SGS4 has a boatload of new features. They were shown at the unveiling and have been getting heavily advertised.
They take a bite out of your storage.
And despite the fancy "available storage" graphics, the truth about Android filesystem allocations has always been what it's been.
You've never bought an Android device with xyz GB that were your storage just for you. It's never existed.
I don't mean to sound harsh and I apologize right here if I sound that way, but 1) I don't understand the surprise and 2) I don't understand how this can be a new concept in the course of buying computer hardware.
If you previously thought that your xyz MB or GB phone that you've owned before was all yours for add-on apps and data, now you know better.
And btw, that 2 GB of ram? You don't get that either. Before Android launches, a chunk goes to gpu memory and another chunk goes to i/o management (example, your radio interfaces).
And that's been that way for years as well.
Sorry. But it just is what it is.
PS - no, the FCC has nothing to do with this. They certify devices with schematic diagrams and part numbers. How much storage is in a part or how it's used, is not their concern.