I used to own an Aesthetix Romulus. It got close to my previous modded/re-tubed Ayon CD-5s which is saying something & sounded more natural to my ears. Music just flows through the Romulus like a mountain stream. It really gets out of the way and let's you enjoy the music. Also, you can see where Jim White has spent the money on this player. The build quality and attention to detail are excellent, and better than Ayon. That is a good value player which has been maintaining solid 2nd hand value.
The beauty of the Romulus is if you live in the states there is an upgrade path..the player can be upgraded to Signature spec (which adds DSD) or even partial Eclipse spec (though note: not cheap). I would think stepping up to a higher end CD player will give you a more coherent, more natural sound vs running your Oppo dac-out to something like an Aeris dac (good though it is). That has been my experience anyway, having ran my previous JVC XL-Z1050 as transport with one of the best Delta Sigma dacs ever made (Vimak DS-1800 MkII).
Another possible option you may not have considered would be sending your player off to either Dan Wright (Modwright) or Exemplar Audio for mods. Though in terms of customer service and resale value, I would lean toward Modwright. Good 2nd hand MW Oppo 105's show up on the 'Gon regularly at more accessible prices. Some food for thought.
