what is the weakest link in my audio chain

How happy are you with the denon player;maybe modding,replacing or even using a external d/a would result in increased low level detail and microdynamics if that is your goal.

My thoughts were just to try another source if your were interested,denon makes a very nice product designed for performance at certain price point;modding the unit,going new or using a seperate external d/a would give you some areas to think about trying.
If replacing: a dealers audition in your system would be the best comparsion,lastly the external d/a is a route I took once and it worked out very nicely as there are always several higher level d/a's for sale on this site;letting you move up to the next level.

Benqsun- If the dealers in your area are doing as you stated;I would bring the denon with me and do the a/b comparsion at the store.
When I got into audio the store I did business with in St.Paul MN policy was to pick up the piece for audition on saturday and return the unit on monday as they were closed on sunday;I haven't bought new in many years and did not know that this practice of doing business has vanished.
Iplaynaked- thats for some insight on the new sales thinking of today.

Benqsun- nothing wrong with that as long as the $$ hit isn't to bad.
Northwoods_maine - nice to hear stores like I was use to are still offering that option.