Dedicated Vinyl system next upgrade?

Hi. I love my system. I really do. I love vinyl and listen to vinyl nearly exclusively via “appointment listening”. I do Sometimes stream and listen while I walk or while working but I love just sitting and listening to my stereo. I believe I’ve arrived regarding finally achieving a great set up and have experienced that vinyl “magic” that audiophiles obsess over. I understand that limitations exist and a great stereo will reveal the quality of a recording - good or bad. The law a diminishing returns regarding  upgrading is something I’m mindful of. I don’t have endless funds to spend on upgrades. My question is - what should I consider upgrading next? Should I ditch the integrated amp considering I’m using an external phono stage? Or should I go with a better integrated amp? Or should I look at a better cartridge? Do I upgrade my turntable or just the tonearm? Do I upgrade the power cable on my amp? 
Here’s what I’m currently working with - and thanks for your thoughts/suggestions! 

Clear Audio Concept Turntable
W/ Hana SL cartridge 

Herron Audio VTPH-2a Phono Stage

Rogue Audio Cronus Magnum II integrated power amplifier 

Kimber Kable speaker wire and interconnects (I forget which model - an entry lever set - nothing crazy) 

Bowers and Wilkins 805 D3 stand mount loud speakers

Set of two stereo REL S/510 subs

Many things can be done for upgraded sound . You haven't mentioned acoustics . If you have not fooled around and invested into a better sounding room then thats where you should start . Carpets , drapes , tube traps , whatever needed . It could make a much bigger differences then any piece of equipment or tweek . 

You have an integrated . Many sound very good but a Good pre power combination will in my estimation sound better . Unless you have something like a Plinius , Mark Levinson or Pass integrated separate units will sound better , although not all , you still have to be careful buying . Your Rogue Audio for the price is very good but even Rogue have their separates . 

You can upgrade your cartridge but in order to be able to extract best performance a better tonearm might be necessary . You have a very good turntable . Experiment with mats .

Your phono stage seems to be excellent . To finish , cables . I use and will always recommend JPS Labs superconductors . They are excellent and sound great with tubes or Solid State , be it speaker cables , intercomnects or power cable . Their Aluminata series are superlative.
 Hope this helps 
 God Bless and stay safe .
The room is 18’ x 30’ with a high vaulted 18’ ceiling. I do not have any room treatment. This is a tricky area for me. Interior aesthetics are important to me. This is both a living area as well as a listening room. I truly hate the idea of hanging RT panels on the wall. I might be able to live with some corner bass traps but my original goal was to build a system that sounds great without making my home look like a recording studio. I understand this poses huge limitations but that’s the deal. I do have my speakers out and away from the back wall. I have played around with speaker/subs placement as well. Thank you all for the great thoughts/ideas, keep them coming if you want but again, I’m not hanging RT panels from my ceiling.
As in a previous response, buy records from 50' & 60's and some from early 70's... also grab the record Dr record cleaner works great if u don't mind spinning the record manually. Buy a good cleaning fluid to go with it, non alcohol. The audio intelligent #6 is a good product. I would not change out either the turntable or the hana cartridge, I think you have done great there. The hana are terrific cartridges for the money, I run the hana el and I love it. I'd go with maybe a nice power conditioner along with at least a high current power cable for the amplifier, maybe try the audioquest thunder and the audioquest Niagars conditioner. Also maybe try a few different interconnects from chord, Atlas, Qed, ecosse....yes I'm partial to UK interconnects lol. 
NP thanks for the clarification. Then we know that you have reached your maximum of treatment as I said before. ;)

Then it is time to measure and identify issues and solve them with a little DSP in the signal path between preamplifier and power amp/s. With that solution you do not need to put any sound treatment anywhere.
  • Better integration between sub/s and speakers by:
  • > by be able to compensate distance/time difference between sub/s speakers.
  • > by be able to use Lindquist steeper x-over filter that he also advocate for.
  • Adjust the unlinear frequency response of your speakers (all speakers has that more or less) or maybe there is a dip that you like.
  • Adjust for unlinear frequency response how your room interact with your speakers.
  • Being able to adjust for "Equal-loudness contour" (Fletcher-Munson curves or international standard ISO 226:2003)
  • Being able to adjust for your own preferred sound preference.
Probably something that i have forgot..

Regarding the integration between sub and speakers.. I am able to turn off my bookshelf speakers. And only listening to the subwoofer. I got very surprised when I could hear faint in the background when the subwoofer were playing the sound of the singer and other instruments that is higher in the frequency range..
And the cut of frequency were at the lowest setting at 40 hz!
I should not be able to hear a singer at all. I suppose the implementation of the knob on my subwoofer were using a shallow x-over slope perhaps max 6 dB/octave.
But with the DSP doing its job and I use 48 dB/octave at 53 Hz. Now the problem is solved with that the subwoofer will only amplifie and play those frequencies it should and nothing else.