Earwig.... I'm building an aluminum airplane as a hobby... these were more of an amusement. Plus they're a non-critical place to practice my aluminum working...
There are no similar bags on the market.... Happy Trail, Jesse Bags, Moto-Sport, ZEGA, Hepco Becker, and others make aluminum panniers... really nice but not exactly the same things... first because they cost from about $800 to $1100 (maybe more) once you've mounted them, second because they don't make any to fit my bike, third... well, they're just different. Boxier, thicker material, different design goals, etc. And of course it is cooler to have *my* bags, fitted to my bike (and my intended type of use). These were sized to fit the camping gear I want to carry, and the standard stuff I'm most likely to carry (gallons of milk and such). The dimensions are a bit odd by normal standards (19"-22"Lx7-8"Wx10.5"D) but they fit the available space and give me about 1500 cubic inches of storage per side. The more conventional paniers would've required an exhaust rework or would've looked goofier.
Most importantly I'm a weird sort of cheap. That's a big part. Huge. These were about $65 out of pocket ($130 including all materials used) including the LED turn signals (not counted in most hard case prices), and don't think I could get equivalent for less than about $500 even if anyone made them for my bike. A set of Happy trails panniers for a V-Strom 650 with mounting hardware will set you back $785 unfinished.
Onlinesmurf... that's a cool idea. My plan right now is to attach tie-down hooks to the cases so I can bungee a tent, or other long package to the tops. It was funny... when I carried the rear brace (the angle aluminum part that ties the boxes together) home from the metal store I did so by strapping it with packing tape to the grab bar on the bike... I'm sure some people were wondering why I had aluminum angle sticking out a foot in either direction...it'd be much nicer to be able to loop such things to the tops of the boxes. Flip side is it'd suck if you got rear ended.

The boxes are sized to allow inserting ~20" items such as a self-inflating sleeping rolls without forcing anything... they are actually 22" long inside along the longest stretch. I can strap a standard 4-person dome tent lengthwise on top of one box... though it sticks backwards off the box approximately 8".
In the longer run (a month from now? After I've used them a while but before I'm ready to spray them yellow anyway...) I'm planning to make some boxy lids that will store a few MSR fuel bottles or other stuff in the lid, and bring the tops of the boxes level across the seat back. That'll allow strapping a load across the seat and both boxes.
In the longest run, I'll probably make new boxes after I've had a chance to use these a while and figure out what I like/dislike... aluminum is cheap and experience is gold.

Ride it like you think owning it matters.