Windows tends to remember what drive letters were assigned to a USB drive/stick, and sometimes that somehow prevents the drive/stick from being assigned a drive letter when it's plugged in. Normally going into Control Panel -> Admin Tools -> Computer Management -> Disk Management you can find the storage device and add a drive letter, & all is well. Adding a drive letter towards the end of the alphabet *usually* makes the problem go away, as long as you only use the same letter once.
RE: Powered hubs... I [now] prefer them for two reasons: 1) if a device other than a USB stick is plugged in, and it happens to go bad, it's more likely that the hub will be toast rather than the circuitry inside your PC/laptop, & 2) as I found out with this motherboard, you are more certain that the correct amount of voltage will be available -- something that cost me big in wasted time and a bit of money.
RE: Extras... I've got a couple of hubs with switches for the ports, which can be handy when you're swapping out drives/sticks -- it's quicker/easier to push a button sometimes than physically unplug the drive/stick. I've also got a couple with wired network adapters built in, which can be handy on WiFi only devices.
"It's more accessible than the ports on the system unit because it's connected at the back"
I use USB ports a LOT, and have found USB extension cables extremely handy. I have a couple [USB 2 & 3] connected to the back of the PC and hooked where I can pull them out just under the edge of the desk. I also have one plugged into a hub at the rear of my desk, which runs around the edge of the desk and is velcroed on the top front of the desktop, and it's been extremely convenient. Note: many motherboards, including the one I'm currently using, have different USB I guess you'd say sources -- some are provided by the CPU, and some are provided by an add-on chipset. So some USB ports are faster than others.
"Some of the flashies are USB 2 and some are USB 3 - it doesn't seem to make any difference."
It depends on the USB port's source [as above], on the USB stick itself, and on the amount of data your transferring. As far as the USB sticks themselves go, there was more emphasis on speed when USB 3 first came out years ago -- today, while some USB 3 sticks are definitely faster than others, to get really great speeds [like my SanDisk Extremes] you have to spend over $100 each.
"are there any recommendations"
There are a few more well known brands that tend to have many thousands of positive reviews on Amazon and are somewhat frequently on sale from around $6 or $7 to $20. Usually I try to find one with a plug for a power adapter but without the adapter to save a few bucks -- I've got more than enough 5v adapters by now. Generally I look for what's on sale and has the most 5 star, and the lowest percentage of 1 star reviews. The one Sabrent model I'd recommend off the top of my head however only has a short input cable that can't be removed, so wouldn't work if you only connect at the rear of the PC case.
"before anybody recommends software or image backups -- we've used this same basic method for more than 30 years. We don't bother with registry or program data under the assumption that programs can be re-installed."
The only thing I can think of that ***might*** come in handy is Win10's File History -- Settings -> Backup -> Back up using File History. You add a USB stick/drive, tell it what folders to include, and set a schedule. Assuming you only plug the stick in once every couple of weeks or once a month, as soon as you plug it in Win10 should duplicate the files in those folders onto the USB stick.
Bonus tip: I've found that the best way to store all my USB sticks is in the tins that some Amazon gift cards come in.
