So as LB says, you should see it yourself, not read a spec sheet. It's the lack of a decent means to see the TVs that requires a scientific comparison to be made for comparison's sake. If you can, look at two TVs in an appropriate setting showing the content that interests and pick the one that looks better to you, ignoring all and every number!
Personally I think it's wiser to do research. It might look fine on display to me, but then I might get home and read about how the TV handles motion terribly, or is dim. I also dont trust myself to know what looks good, if that makes and sense.
Many times I'd probably never even know, but I'd still like to know I got a good set. Heck a good example of this is input lag, I dont think I or most normal people can tell (offhand, anyway) if a TV has high input lag. Nonetheless I make sure to get one with low input lag because I know that's a thing. Make sense? Probably not.
Another example is PS4 vs Xbox One. Exclusives/networks/UI/friend list aside, most people probably cant tell at a glance Xbox is rendering lower resolution in many cases. They need research to know that and probably decided PS4 is the better buy.
The other thing is I'd be suspicious of how the sets were calibrated in a display environment. That's why as I understand TV's are all set to max brightness on display. But what if one wasn't, and you chose based of that? So that's another reason I dont think you can judge at all by how sets look on display in a store. Which you didn't single out in a store, but that's the only way most people are going to be able to compare many TV's.
Of course there's also a useful shorthand for research which is, buy a quality (read: more expensive) brand. In general, if you buy a Samsung or Sony TV you are going to be getting a quality product. This is good quick advice I give people about buying almost anything, buy a good brand you should be ok. Good brands dont tend to put out any outright junk products (although of course there could be exceptions).
But it's different for all. True laypeople, almost any TV will serve them great and they'll be happy with it. Or, simplistic factors like the remote and UI will play a greater part in their satisfaction than advanced picture quality.