KEF Blade -- how good are they?

I believe the reviews that claim the blades have a higher ceiling than other speakers in their price range. Kef has been improving on the uniq driver for something like 11 generations and the first one that was in the r105/3 was no slouch. I would think getting the electronics matched to the speakers for a rooms acoustics will make or break them, just like any other system. They're on my bucket list.

I heard them at a show in a large room—didn’t do a thing for me but I’m not often impressed by systems I hear under show conditions.

I listened to some raidho’s at axpona, the D1.1 and D5.1, I loved the 1.1 and couldn’t get out of the d5.1 room fast enough. I really believe speakers need to be the right size for the room to make a fair assessment. Wilson speakers generally sound great at shows because for 1 thing they show their speakers in appropriately sized rooms and actually know how to place them. 

The Blade is the best sounding speaker I’ve ever heard in a real world setting(my room, my gear) and there’s been some impressive contenders.

I liked what I heard from the Blades on two different occasions -
-blown away by their sound stage and sheer power over the room.
-did not care for their overall tone which was an odd mixture of warmth and coolness.  lots of midbass warmth yet at the expense of transparency.  upper midrange had a cool metallic after taste.  
-take care in amplifier partnering.  something like pass labs might work.  

Yes, I agree. The po had them connected to tubes and the balance was warmer tho’ the hegel is a pretty good partner and with carpeted floors, acoustic tiles over Sheetrock and plenty of distance from the sidewalls these do well however there are some recordings that I would consider your description of the upper midrange spot on.