How to identify my weakest link?

@avanti1960 yeah I looked at the Lyra carts. From what I’ve read, I might be better off with something a little less analytical given the speakers I’m running. 
 

@mulveling Thanks for the ideas. I think I’ll start with cables until I can decide on a cart direction. I’ve also thought about going the Clearaudio Concerto MC given I’m already running the Ovation. So many options. 

The Benz cartridges are very musical, with a touch of sweetness and warmth - not at all analytical. They’re excellent for the money especially if you peruse the FS ads here. Any of their "L" (low output) models in a Zebrawood or Ebony body are pretty stellar. And a piece of cake for your Herron to amplify (well except for the Ebony TR but that thing’s crazy). Could be a great sonic match with your table, amp, and phono stage (and possibly speakers) all falling on the clean-neutral side of things. Rogue tube amps are certainly not warm nor "tubey" sounding. I don't expect any difficulties for the Benz in your Magnify arm, either (which is an arm I kind of like - what I hated was the all-magnetic Clarify). 

Nice system Paul! I think your inclination to look at different speakers and, if necessary, a complimentary amp is spot on. It sounds like you have some issues with the speakers that are beyond the ability of tweaks to address. Personally, I’m not a fan of B&Ws—you can do better without spending a ton of money and probably find something that works well with your integrated. Generate a shortlist and take your amp to a few dealers to see whether something else tickles your fancy. Good luck!

I would treat your system with High Fidelity NPS 1260

I should also add that I would absolutely benefit from some room treatment but to be honest, aesthetics matter more to me. I’m just not interested in hanging clouds or placing random panels on the walls. My goal is to make the stereo sound as good as it can without making my living space look like an audio room. 

I have to agree with @elliottbnewcombjr , and with the concept @tomic601 presents, and love that room @tomic601 , but would consider a panel behind your listening chair. I think you will be astonished at the difference. You don't need random panels, but some well placed ones, custom matched to your environment, is going to do more good than anything else. I get it though, aesthetics are part of the enjoyment as well. The problem is change will just be that. Change. Not better, not worse, just different.

Speaker placement if not ideal is going to be a big improvement. Take @elliottbnewcombjr , get an SPL meter, or a microphone. Its hard to guess at proper bass.

I assume you are just using the subs panel for bass management? With the SPL meter or microphone and a way to generate tones, you will be able to dial in more accurately.

If I am understanding your system correctly, the weak link is bass management. I assume your mains are running full range. How loud do you listen? If you like volume, that is going to push the B&W into much higher distortion in the bass. Limiting their low frequency extension and letting the RELs handle all the <80 may be preferable depending on listening volume. DSP for bass management at least for the subs will be a step up too.