I say all of that to say this: when evaluating a horizontal center channel you know you are already starting with a disadvantage compared to a typical bookshelf or floorstanding speaker. As I said, if one is able, they should orient the center channel vertically (unless, in the rare case, the speaker is designed solely to be oriented horizontally).
Hope you get to review the KEF RC2 one day Erin. Given the off (vertical) axis placement realities of horizontal centers, I think the concentric design would prove to be of substantial benefit, especially if it performs in line with the R3.
This is, in a roundabout way, what lead me to this thread. I've been wondering, does the R5 only offer more bass due to cabinet size? On paper + given the nature of a concentric design, R2C and R5 are basically the same speaker. In my specific case I have a R2C I barely use, because for TV/movies R3's image so well that I get a phantom center with almost no effort. Even in cases where that's not sufficient (e.g. content with a lot of whispering like A Quiet Place), Denon's dialog enhancer gets me where I need to be.
Additionally, my system was built around 2ch upmixing and I have yet to find any upmixer that utilizes a center to my liking. The sound always seems to get 'pushed inward' as if the shared L/R, mono-ish aspects (snares, basslines, lead vocals) are sucked out of L/R and placed solely in the center. Dolby center spread kind of has the right idea, as well as offers superior front wide support compared to Neural:X, but overall my preference is Auro3D w/ center off.
To that end, I was considering getting another R2C and bringing my own stands + small sub to make a pair of R5's for use elsewhere but I can't find any vertical directivity plots of R2C to confirm my suspicions.
@hardisj are you interested in testing R2C? If so, PM me and let's figure something out. Maybe the result will inspire someone to submit R8a's
Not many comprehensive Atmos measurements out there AFAIK
Strange to me Kef is so forthcoming with FR on the R-line except for that one model, perhaps they feel it might come off as a poor performer if consumers don't understand it's intended use case. Just spit-balling here as I have been told by one well-known (in the USA) manufacturer "we stopped publishing [CEA] because it just confuses people."