APTX HD

Perhaps I should add that the receiver is attached to the amplifier (IOTAVX SA3 & PA3) and LRS speakers.

Im getting good results with Aptx hd, what receiver are you using? 

While Bluetooth has come a long way over the years APTX HD (and LDAC for that matter) is still inherently lossy. It's convenient no doubt but the sound quality is lacking in comparison to lossless streams over WIFI. A streamer like the Bluesound Node 2i would be a nice step up for you and wouldn't necessarily break the bank.

Melvin

The OP has told us that he prefers Headphone Listening, without wires.  That pretty much confines the OP to Bluetooth or AirPlay.  I have the Node2, and in the same system I also have an Audioengine Bluetooth DAC.  Without question, when it comes to Bluetooth, the Audioengine blows the Node2 away by a wide margin.  I believe that the Node2i uses the same Bluetooth codec as the Node2, and the OP already has a Bluetooth DAC that seems to work well, so the Bluesound doesn’t seem like a good solution for his problem.
  Or does the OP have a problem?  I suspect that there isn’t much that can be done to improve the current setup with respect to Bluetooth.  You can experiment with better Bluetooth headphones—the latest Bowers and Wilkens get good reviews—but as Melvin notes, it is inherently lossy so there is a ceiling to what the OP can achieve.  I would just stop suffering from Audiophilia Nervosa and enjoy the music