@tommylion I read your post with the uppercase quote in it. Its an interesting position to be in, "...IF YOU RE NOT TOTALLY HAPPY WITH THE PERFORMANCE..."
How do you measure "totally happy with the performance"? Against what? You only hear tweak improvements for a short time until you get used to it, then it becomes part of the norm. It becomes a case of chasing the impossible if whatever improvements you hear become part of the background.