How good can it get, really? - my stereo sounds amazing!

No point around here isn’t worth missing it seems...If your room doesn’t need treatment because its inherent acoustics are fine...not dead, but fine...it might even sound like a room, then don’t worry about it. If you live in a large tomato can or a raw concrete bunker you might need some treatment...in that case treat it. Moss...grow moss. I’ve worked in recording studios and mixed live shows for decades, and I prefer less dead rooms. Removing furniture and CD boxes and replacing everything with sound deadening "treatments" is simply silly, and if you experience a weirdo with cheap headphones without ear pads listening to a walkman in your room, that’s geoffkait...remove him...the sound will improve immediately.

Somebody is having a Machina Dynamica moment. 

taras22
I agree that carefully selected furniture can help, but this is no substitute for good quality acoustic treatments. Most I build myself, but I did recently buy some of the best quality diffusors for a song and was very impressed. If you have the ability to DIY, then treatment doesnt cost much.

audiozenology"Furniture is not a replacement for room treatment. It can even make things worse"

This "information" is so wrong on so many levels, aspects, and issues that it is hard to know where to begin a good place would probably be that furniture is a kind of room treatment even if that is not the type that you like! Some people "like" the sort of sculpted "egg-cartons" and other "doo-dads" that often is used in official, commercial purpose designed "room treatment" but none of these "treatments" contain any magic, fairy dust, or voo-doo spells and there is nothing worse and I do mean nothing than an overdamped, overtreated, over analyzed room and that is very common when relying on these "professionally-approved" commercial products because the company’s often want to sell you just one more "corner trap" or special "diffusor" thingie so whether using these products or furniture you’re room can be "over-done."

I understood the question of the OP as seeking quite significant improvements to the system. Obviously, I was wrong; when outlets and power cords become the primary objective, then one is merely tuning up the rig, not making great advancements. Adding a couple of subs would be a nice improvement. Make sure to get aftermarket power cords on the system, or else a lot of performance will be left on the table, even with the subs. 

I support outlets as improvements, so going that route will make a difference. But, let not the OP think he's really gotten close to the ultimate. No, in absolute terms there are dozens and dozens of rungs on the ladder of system improvement. Maximizing the set of components and speakers you have is a different situation. You can only take a defined set of gear so far, but if that is the goal, it is fun and can be very efficacious. 

Regarding the recommendation of those who said essentially, be content; it seems you were right, he does not wish to venture far from his current system. No shame or problem in that. 

I never promote foolishness and irresponsibility in pursuit of system improvement. I am a big proponent of contentment, as I give generously to Christian programs, budget monthly (just did so yesterday), and have allocated a consistent amount of funds over the years annually to achieve what I have over time. So, if the goal of the OP is to primarily hang where he is at, there is nothing wrong with that! Typically when I discuss the necessity of spending more, upgrading major parts of an audio system, it is within the context of the performance of the system, not associated with the individual's personal financial situation - unless they specify, which in this case he did not. 

Strictly in terms of performance of audio systems, though, I see many audiophiles ignorant of just how vast the performance spectrum is. I think I have answered that question thoroughly enough.  

Have fun with the upgrades!   :)