I've noticed a lot of people saying this and suggesting external drives are the way to go but they aren't anywhere near as elegant as a small Sandisk thumb drive. Why is this the case though?
It doesn't. Wii U mode supposedly kills flash drives because it keeps writing to them in sleep mode. Wii U mode can't read FAT32 formatted drives though, so it shouldn't be a problem with drives that are used for vWii.I've noticed a lot of people saying this and suggesting external drives are the way to go but they aren't anywhere near as elegant as a small Sandisk thumb drive. Why is this the case though?
And, you shouldn't put your USB to wbfs format. why suggest that? if you do, you probably didn't read proper guide again.
Just to add to what was already said... a Micro SD + USB adapter is a much better option than flash drives anyway. You generally get much faster speeds for less money with Micro SD when compared to the typically slower and more expensive flash drives.
Of course, a powered USB hard drive is still the best option overall (speed, size, price per GB).