Well, I do give wongmb credit for having the balls to post his experience. That took a fair amount of guts knowing he'd get hammered pretty hard.
I thought about Ethan's comments regarding comb filtering but my gut feeling in wongmb's case is that it's probably not the case unless his room is pathologically bad or that the listener just happened to be sitting differently enough that issues of nulls truly became the issue. He's got some room treatments in there...maybe not the right ones or maybe not in the best or better locations, but he's done something and I doubt it's been to the detriment. This is why I try to nudge and prod him into embarking on a learning curve with regards to measurements.
Hi-end, mid-fi, entry level, revealing, and all that becomes oh so subjective and is so often tied to what one's budget was. As satisfied and proud you are of what you own, there's always someone out there more than willing to drive-by and piss on your choice. Tweaking in the sense of cables, treatments, contact enhancers, fancy outlets, lifts, special shelves, etc. are a way that many people use to create a magical force field that deflects the piss.
Unfortunately, there aren't enough reviewers out there who are comfortable in correctly interpreting measurements or who understand basic and fundamental issue regarding how our auditory system works. For that matter, there aren't that many people on the flip side. At least in most of our earlier education, some teacher showed us how our eyes can play tricks on us, how sensations of hot and cold can be tied to the environment that one's in, and so forth. With hearing...I don't remember any experiments. Realizing that one isn't in complete control of one's senses can be disconcerting.