@joentell made a really good point in his video that I want reiterate.
A few inches bigger in each direction is actually a significant increase in size (total volume).
KEF KC92 is 9.68in. x 10.07in. x 9.76in. = 0.55 cu.ft. (15.6L)
SVS SB 3000 Micro is 10.9in. x 11.7in. x 10.7in. = 0.79 cu ft. (22.4L)
Only about an inch bigger on each side but about 44% larger.
SVS SB-1000 Pro is 13.5in. x 13in. x 14.76in.= 1.5 cu.ft. (42.5L)
Which 2-3 inches larger on each side, but almost twice the volume of the SB 3000 micro and nearly 3x the volume of the KEF. Of course you'll pay in price and likely ultimate output especially at <30hz. But if you can fit two of these things in the right parts of the room, I can see the payoff being there for many people.
I want to be able to get two of the KEF, but I can't justify the price, or maybe the proper way to state that is I can't afford it. I think I can with the SB300 micro, and I was struggling to see where I would realistically put two of something the size of the SB1000 (was looking at Rytmik). I'm more than comfortable with the trade-offs to the 3000 micro, cost and performance* VS a traditional 10"/12" smallish sealed sub. Plus it means getting two of them into my space much easier. Maybe it' just me, but I'm feeling like they hit the price target for something like this on the nose.
*I'm still wanting to see Erin's results before I fully commit to that statement.
I need to get one more thing off of my chest. The SB 3000 Micro is
not a 10" cube, in fact, it's almost the exact volume as an 11" cube. Grumble grumble, cruse words, marketing, more cruse words, get off of my lawn.