Slightly off topic, I too had a similar experience in the recent past. I was using KEF iQ7 speakers for stereo in my living room and I was not at all happy with the low end and overall performance. I was almost going to sell it off and get an expensive and better speaker and electronics. Before I did that, I just tried a small experiment.
1. I build the DIY Pass B1 Pre and CNC phono. (This is one hell of a performer

, I just can't thank enough for this wonderful DIY kit developed by Sachin, Om and others).
2. Moved the KEFs to my dedicated listening room with acoustic treatment.
3. Did some measurements using UMIK and REW and adjusted the speaker position and toe-in to make it sound "flat" in the room.
You will not believe the way those KEFs transformed. They transformed themselves into a "BEAST". They started sounding very live with decent bass. When I was using KEFs in a living room setup, it hardly produced any bass.
I had a friend of mine visiting me yesterday and he was really surprised to know why would I ever wanted to upgrade my setup. He said they sound pretty fine.
Here is my 2 cents from my experience
In Audio, you are always in for some BIG surprises from the least expected things

. And its not always the most expensive stuff that can give you the best sounding system, there are other factors that can make an "inferior" system to sound much better. For me, one of that factor is the room and acoustics

.
I don't think I need a stereo upgrade any time soon

. I am still working on the best position and placement and some acoustic mods using REW and looks like I am almost there.
-John.