I was testing Plato and it doesn't save any of my reading "progress" info if I quit the program or reboot from the menu.
If I select quit from the menu, it will go back to kobo original menu but display an error message saying that "my SD card is not format fat32" and all my pdf and epub disappeared. I have to power down and then power up to get back the books.
Also, reading pdf seems to be not as "clear" as original kobo reader.
The great thing is it turn page very fast and I like the "crop" function.