[GeoffR]

Originally Posted by Crusader

With sideloaded files do you need to copy the ePub files to a specific directory on the Glo?

No, you can put them either in the root directory, or create your own directories.

Is there any downside to storing the files on a SD Card instead of the Glo itself

The main downside is that some firmware versions have had bugs or limitations that only affected books on the external card. Also, even with firmware versions that handle books on the external card correctly, there is a delay when booting that depends on the number of books on the card, a delay which doesn't occur if the books are on the internal card.

Are you able to store notes/highlights etc. for books stored on the SD card?

Yes. Annotations are stored in the main database regardless of where the books are located.

Any recommendations for a specific brand of micro SD cards that work best with the Glo?

I think the Sandisk class 4 and Sandisk Ultra class 10 cards are good. Kobo use a Sandisk card for the internal storage.

If the reason for using an external card is simply to increase storage space, rather than for the ability to swap cards, then there is the option of replacing the internal card with a larger one rather than using an exernal card. I have an 8GB internal card in my Glo and so I rarely use an external card now.