I run 590s for L/C/R, 580s for surrounds and 530s for my elevations speakers powered from a rack of QSC CXD4.3 and CX404 amps. Low end is SVS.
Each time I have moved up a speaker 530, 580 to 590, it's been like a vale is being lifted off the speaker. I think the lower models suffer a bit from the x-over having to shelve down the compression driver as a whole so it does not out run the bass driver. I think it takes a bit of life and sparkle away. The output levels of the EON speakers with the same driver (albeit different horn, crossover and I thought different phase plug or something) gives you an idea the ear splitting output and efficient a true compression driver can do. And this is low output one by any JBL Pro standards.
I run all my speakers with the bass port plugs in to lesson the bass bump and also deal with reducing a bit of room gain from positioning where they are pushed back more into some corner loading than I would like.
I went with a 3rd 590 for my center, right now I have it horizontally belowr my 120" screen elavated on a stand. Plan is to go A/T screen but just has not happened yet, so this was going to be temp. Previously I was running the klipsh RP450c, then the SVS the ultra center before... its now upstairs with the SVS towers now in the living room for the kids. There was no comparison between the options in any respect, utter knock out. I know the placement horizontally is not ideal, but the dispersion and what ever else they did to this speaker it works and sounds incredible. I suspect the same resonace and horizontal dispersion of the 530 exists in the 590, but I don't hear it. I think the 2.5way xover might also be helping a bit limiting high mid bass from the lower driver. I have a dark grey room with a grey 3D ALR Aeon screen so the unconventional grey drivers of the 5 series look menacing with the grills off. The asymmetry of the tear drop design of the 590 on its side I live with, I could wrap some A/T cloth to 'square' it up, but I love seeing that massive horn ready to kill me if it ever decided to. I think this series suffers being designed several years back missing a real center channel option. Center channels where not the anchor of the systems we use them for today just a few years ago in the early days of home theater. I tried the 530 as an option with the 590s flanking, and it was decent, but did not match the SVS Ultra Center by a decent margin for that application. It also visual looked off flanked by the massive 590s..
The 530s I just temp mounted as my elevations, I have them crossed at 100hz right now. I am following more of an auro3d layout plan at 30 to 40 deg above my mains in expectation my next pre-pro will be auro3D capable. Running the way I am, the 590s with the 530s as elevations sound incredible. As I understand Aura3d will drive more full range content than what atmos does so that will be interesting.
I did run my 530s with my SVS subs for a while. They were great!. I truely enjoyed them, they sounded better and better the more power you threw at them. The higher xover and plugged port seem to eliminate the port and chuffing issues people brought up the way I had them set up. They would hold together to a more than decent volume levels at 80hz. Although, when I grabbed the 580s on sale, the difference was huge, not just raw SPL but mid bass snap, vocal presence and highs all noticeable more present. 580s to 590s same thing.
At the end of the day, I love all these measurements and tech discussions as a tweaker geek (toying with going full active as well). But what I can say, at the sale price of the 530s, the sum of the whole is just something awesome. I am sure there is some bias here, throwing back to my old days running some serious JBL pro tour and install rigs, but for the money I have invested, vs the performance level of my theater, it's off the charts IMHO.
Next is some REW turning and addressing more room acoustics. On sale, I just don't know what really touches these. (Well other than having to get creative with elevating the 530s which have no mount option and are certainly not light). I just can't see that much value upgrading in the near future. Other parts of my system, room acoustics and decor will have far more impact.