UPDATE
I bought another keyboard case and it arrived today: this one (HOU F22).
Verdict: 4/5 stars, definitely better for my purposes, only loses one star because I'm a perfectionist and it has two minor snags.
What it is: it's very much like a regular iPad Mini Smart Folio from Apple, only with a keyboard on the inside (like the Magic Folio for iPad Pro/Air, rather than the Magic Keyboard). The keyboard layout and design is very Apple-like and indeed the feel is way better than any other iPad Mini 6 keyboard I've tried. The keyboard connects via bluetooth; auto-wake on any key, and auto-sleep if you fold the cover back behind the iPad. The back shell sticks to the iPad using magnets, and the upper half hinges down to form a stand (like the kickstand on a Microsoft Surface, or the back shell of the cover for the new iPad 10).
It's lighter than the ARTECK or Snugg keyboard cases -- nearly as light as the Smart Folio itself: the iPad in F22 case is only about a millimeter fatter than the iPad in the Smart Folio.
What I don't like?
(Trivial) No blacklighting (but light weight is more important to me)
(Trivial) The magnetic attachment of the back cover isn't quite as strong as with the Apple case (the iPad won't fall out if you lift the case by the keyboard half, but when you fold the kick stand back you might need to hold the iPad to keep it from detaching from the other half)
(More serious) The keyboard charges from a USB-A socket using a proprietary cable: instead of a micro-USB tip plugging directly into the keyboard, it uses a magnetic attachment of a type I've never seen before. Obviously this enabled them to keep the keyboard nice and thin, and it duplicates the charging function of the official Apple iPad Pro/Air charging/keyboard connector on the back of the iPad, but it's a unique cable type and if I lose it I'll have no way of recharging the keyboard case.
On the other hand: the F22 claims a 1-2 month battery life, so if I leave the magnetic charger cable plugged in permanently by my desk I should be okay for travel.
Overall verdict: the F22 is thinner, weighs less, has a better keyboard feel, and is more "Apple-like" than the ARTECK or Snugg keyboard cases. Only real drawback is, don't lose that cable.