This is by far the best keyboard case I have had for an iPad Mini, having had various iterations since I got mine when the first one launched all those years ago. Upgrading to the Mini 4 prompted a new case, and Logi(tech) did not disappoint.
The keyboard holds its charge for a good amount of time, and the magnetic seal is just strong enough to keep it closed, without making it impossible to open. The key action also feels surprisingly solid, and I was able to acclimate to the tighter space more easily than I did on my 9" netbook of old. It also rarely disconnects from the iPad, and doesn't suffer the input lag that other Bluetooth keyboards I've owned have suffered. The case also feels solid, gripping my iPad tightly and doing a very good job of protecting it (while it's no Otterbox, it feels incredibly secure for a plastic-and-canvas clamshell case). It also has a very low profile, which maintains the appeal of the iPad mini in general.
It's important to note that you should only purchase this case if you have an iPad Mini 4. The footprint has changed between versions, and it won't fit right if you have an older version (I originally purchased the version for the Mini 3, and my Mini 4 wouldn't fit).
The only complaints are minor: the size of the keyboard requires a pretty specific positioning to type comfortably--trying to type on my lap or any uneven surface had proven challenging. Further, the case is not conducive to holding the iPad as may be required for some games (playing the port of FFVII has taken adjustment, and FNaF 1 currently requires the iPad to be upside down relative to the orientation of the case). The case does not have any way to secure itself open in any configuration besides the one shown, so you'll need to hold it open for those things--thankfully, it is light and thin enough to where this doesn't represent too much additional effort.
All in all, this is a great case, and I will be sad if it does not work for the next version of the iPad Mini I purchase.