I am pretty happy with the current setup, but know everything degrades over time whether or not it gets used.
My system is pretty old and vaguely recall them finding a similar setup in one of the pyramids.
Don't listen/watch as many movies as in the past, but if I can improve the sound quality I may be interested in upgrading.
Don't want to upgrade for the sake of upgrading.
If upgrading a speaking I don't want "Hmmm, not sure if it sounds better" but rather "Wow, I must have had wax in my ears before." and I am not talking loud but quality.
More than likely actually any upgrades will occur in stages meaning upgrading one piece at a time (ie, receiver, fronts, center, rears....)
Room size :
Couch is 10-13 feet from tv speakers
Rear speakers are 16 feet back, hung from the ceiling (9ft) and pointed toward the sitting area.
Figure the room is about 15 feet wide but sitting area in the middle 8 feet.
Equipment
TV : 75 - inch Samsung Q80T - (NEW - has eARC port)
Subwoofer : SVS SB-1000 (NEW - needed a small sub to fit in a specific area and this one worked. They do have a 45 day trial period as well as upgrades if need be.)
This subwoofer is replacing a Definitive SuperCube III which worked well in this room.
AVR : Denon AVR-1700 (great receiver but can be difficult to setup or reset when wrong buttons pushed. Wouldn't mind a more user friendly receiver.)
If this is still a decent receiver, I will manager with the interface as I have done over the years.
Front R/L : Definitive Mythos GEM
Center : Definitive ProCenter 100 MK II
Rears : ProMonitor 80 MK II
As far as budget, well that depends on what upgrading gets me.
It will get used once/twice a month on movie night. No need for a $5K system.
For regular TV, the Q80T is decent enough to not need surround.