While "tweaking" is pretty much where I'm at right now (Heritage towers + tubes = exactly what Paul K said it should be in my experience), and I haven't even gotten to room acoustics, despite the fact that the room is an L-shape with all kinds of outcroppings and such that really disrupt any kind of nulls, I'm still curious as to what folks think it would take to bring the system to "reference".
What, specifically, do you not like about your speakers? The complaints you have may be caused by the room and speaker placement. I would suggest starting by marking the present locations with painter's tape, then rotating them in small increments, looking at the room as it might impact the sound. Where are the points of first reflection and what materials are in those spots. What are the room dimensions? If one speaker is near a wall and the other isn't, reflected sound from the side close to the wall will arrive at almost the same time as the direct sound, but sound from the other side will be delayed by roughly 1mS/foot of additional path length, which causes 'comb filtering'. That can manifest in many ways- in the case of my room, it caused the pressure at one ear to be the inverse of the other, making it feel as if I was driving up a mountain (with ears popping), but only one ear. If I moved to the sides, it would come and go, corresponding to the distance from one point to another.
I spent some time moving my speakers and making notes, as well as using Room EQ Wizard to see what was happening. That removes a lot of guesswork and is a great learning tool for making measurement coincide with hearing. I really didn't like using my system before I moved my speakers but that wasn't the only problem- I had some deep notches in the response that needed absorptive material panels to tame. Once they were in place (and I saw the changes in the response on the screen when using REW), I haven't touched anything since and I enjoy the sound, very much.
If you want to experience the feeling, connect a woofer to an amplifier and play something with bass, then turn the driver so the face is at a 90 degree angle to your body. This pressurizes one side and rarefies the other. Once you're aware of the sensation, I suspect you're not going to like the sound from many systems because it can be uncomfortable. It has helped me solve problems in systems because I have worked in audio for over 45 years, but I really don't like the feeling.