For installs just get the cheap ones with decent speeds.Just install once every now and then from the USB... The idea of running W10 from the USB I assume is a stop gap emergency solution to get a dead PC up and running again to pull off files, etc...?
4Gb is too small for the new OSeses, they are about 5Gb so you need at least a 8Gb usb to make a windows installation media.I use an ancient Kingston DataTraveler. Not sure how relevant it is in a discussion today. Even if that particular brand were still available, I'm sure the guts are all different. You might want to checkout closeout style 2nd party dealers. You may be able to get fairly low capacity drives very cheaply, so if they don't work, you aren't out much money. Even something like my 4gb drive is useful for sneakernetting documents and stuff around.
edit:
Amazon has a bunch of generic Chinese multipacks pretty cheap. Good reviews for whatever that's worth. I'm thinking something like a 4gb drive isn't gonna have fraudulent capacity, or otherwise be fake since it's already about as cheap as it can get.
Look up a guide on rufus, it's one of the best tools to get windows and other things on your USB, and no any free space left can be used as a normal usb to copy files on.Thank you for the recommendations.
I'm assuming that if I make a Win 10 drive then that's all I can have on there and it still load correctly, yes? Would you agree a 32GB would be big enough for an OS loading drive? I'm assuming people make a single image of the latest build (however that is done) and then keep that drive for reinstalls, etc... Am I understanding correctly?