The Bose system comes with the package I am ordering...not available without it....

i am not pleased listening to XM satellite radio because the treble is much to intense..

I am an audiophile like many others here, but for me, a name should only lead you to listen to a specific brands products in audition - not to buy something without first listening. Once you listen, everything else comes down to what you are willing to pay for, personal taste and what kind of music you like to hear.
Most would agree that Martin-Logan is high end stuff, my brother loves it, I don't. (But we both love my Mirage OMD-28 speakers) So the fact that many of us here look down on Bose should not make any one who is satisfied with Bose decide to upgrade. If you like your Bose - God Bless - you will save the ridiculous sums of money some of us have paid to upgrade. So just listen and enjoy, and ignore the yapping of the audio nuts like me.
It is entirely possible to upgrade your speakers and amps but leave the head unit in place with everything working seamlessly together.
I have a 2013 Sport Touring with Nav. I upgraded with an Audio Control LC8i - this is the heart of the system and makes it possible to use the head unit with aftermarket amps and speakers.
Even with the Bose in place the best thing you can do to improve your listening experience is sound dampening. Anything and everything in the car will sound better with less noise in the car

Not sure how much headroom the Bose H/U has with output voltage for signal and using an Audio Control can possibly add alternator whine and with amps along add ground loop, have you had any install issues and noise using the LC8?

No I have not had any issues with whine or interference.I suspect the cabling plays a major role here though I can't give you specifics regarding my cabling off the top of my head as it was done by a professional shop.
I will say though that I am only leaving the Bose head unit in place temporarily to simplify the install and due to budget constraints.
I have no doubt that, despite the massive improvement in sound quality with what I have done, my quality is still significantly restrained by the head unit.
Garbage in, garbage out as they say, and as I have not been able to find info on the BOSE DAC, I can only assume it as as inferior as the rest of the system.

I am open to suggestions regarding a premium double DIN head unit. Not just regarding pure audiophile quality, but also the quality of the user interface, automated sorting of USB music files, and versatility in handling audiophile codecs such as FLAC, WMA lossless etc.

Even if someone is satisfied with the bose system once they hear a better system they could than be even more happy with that system. Most bose owners do not know what they are missing until someone shows them. Unless they just do not care.

missing the reproduction of beautiful Utopia Be Focal speakers.

I remember when the Boston Acoustic Z's speakers came out, so long ago. They were the best on the market for car audio, sounded so good.