How far TV image quality really come the past 5+ years?

The reason I'm asking the above is twofold. Party because of my current tv set and also because of the lack of any real information about this in magazines, reviews or forums.

So first of all: I own a Sony 46W4000 TV, which might sound familiar to you, since it was one of the best Full HD TVs at that time, which was 2008. That seems like ages ago, and it is. Looking at the long list of features that my TV is missing compared to any mid-range model currently on the market, I'm almost embarrassed that I didn't upgrade yet. But I still don't see that image quality wise TVs have leaped forward the past couple of years. But maybe I'm wrong, which is why I'm asking you.

As we all know, the internet's full of review websites covering all the latest and greatest technologies and often the reviewed product is compared to its predecessor or maybe even the one before that. But what about 5 years ago or even more? I cannot seem to find any information on that.

Sure, if I mention some of the technologies my TV is missing, on paper it's no competition: LED backlighting, 100+ Hz, 3D, thin bezels, Smart TV, EPG, Wi-Fi, DVB-tuners, and much more.

An yeah, if I have to be really picky about the IQ of my TV, it has to be that the black levels are not the best. But apart from that I cannot see any real difference in quality when I'm standing in a shop and looking at all the top models currently available.

So can anyone comment on this based on personal experience or even back a certain conclusion with numbers? I'm very curious about this, because even though computer screens can be easily compared looking at the measured values like Delta E and such, for TVs it seems like reviewers just don't care (but should they?).