If you can't get a dedicated listening room or install acoustic treatment, whatever the reasons may be, then by all means, try to make it up with equipment alone. However to try to talk yourself in believing that a properly setup room is unecessary because of esthetics is laughable at best. It's like preferring wall "art" that matches your furniture. I'm all about substance over fluff, but it's just me. Obviously everybody is different. What matters most is to enjoy your system no matter how you do it. My house of stereo may look like a mess to some, but it's a beauty to me.
If you have a nice system why do you really need room treatments?
Yeah you may need an absorption panel if your room is completely open, ie. No rug or furniture, ie just lonely single chair. But if your system can't cut it in any room then it's a system problem and you should be able to discern a good system regardless of the room. Unless you put it on the roof of your apartment building but the Beatles seemed to have survived that effort
I think people go nuts with all this absorption acoustical room treatment stuff and it looks kind of awful. Once in a while you see a really cool looking diffuser panel and I would definitely want one. But to have a system that works really well without any of the acoustical panel distractions is a wonderful thing.