Ah, the french Giga Octet in action
It will become much harder to get a 16GB card over time, but I think the 32GB cards are officially the maximum size of SD-cards supported by the Pandora.
So, it would be useful to have official releases fit on supported SD-card sizes.
Weren't there tricks to maybe use larger cards, like formatting FAT32 to 64GB cards? Still, it wouldn't be recommended as people probably already have an existing Pandora setup which has smaller sized cards.
Because a byte isn't always 8 bits ;^) It depends on the architecture.
I use 64 and 128 Go without problem.
For the filesystem, SL4P is not on FAT so there's no limit.