So how much is the JBL RC?
Too rich for my blood.
I think that if I'm going to spend that much for room correction, I'd go with the
8-channel ADA Trinnov unit. Alas, it costs like $1250 a channel. Still, a cheap AVR with preouts for source switching and codec decoding, the Trinnov box for room correction, and actively biamped mains...that sounds fun!
Well, even if the flagship JBL RC improves SQ, the question is "how much" ?
I guess for those with "terrible" room acoustics, it might be significant and worth it. But for relatively decent rooms?
My experience is consistently that it's still significant and worth it. Even when one already has mains that have controlled midrange directivity and are properly placed, along with multisubs calibrated to give ± 2dB performance (variance excludes any boost from "house curve") from 20-200Hz.
And yes, that includes Audyssey, though that's mostly because one needs to run the Audyssey calibration to access their really cool bit of software, DynamicEQ. That's a godsend for people who often listen at lower levels.
Others may differ.
Because you base all your opinion on objective graphs.
No. I base my opinion on
actual personal experience with several different room correction systems.
Note that ARC, Audyssey (home and car!), and Trinnov are all represented in my room correction mike pile.
(And yes, despite all that audio kit there's still money in that little Montblanc wallet.

)
Pioneer, Yamaha, and sadly Harman Kardon don't have serious products on the market, so I've seen no reason to give them a spin. Though one mike is actually missing, I guess: the receiver part of the
Pioneer Elite EX500 AVR and SACD/DVD-A player set I've kept in my old bedroom at my parents' house since 2005 or so has an early-2000s variant of their RC system, M-whatever. It has a little bubble mike so unsophisticated that it has a clip on the back: not even a threaded hole for a tripod! That RC is, as one would expect, somewhere between ineffectual and deleterious.
Besides, reviewers providing meaningful objective data won't stop people from preferring one thing over the other, will it? Many people still seem to like crappy speakers with big sound power problems in the midrange, don't they?
Now. if your argument is simply that seeing the data will lead to perceptual bias towards the flatter ones (or alternately, towards the ones with more bass), that's more interesting. I think that may well be true, but I don't particularly care.