The basic answer to your question is that legitimate LED retrofits for halogen headlight bulbs are gradually becoming technically feasible, but we're not quite there yet. We're still in the early stages where a few of the LED retrofits work passably-to-reasonably well in certain headlamps, but we're still not to the point where there's an LED retrofit bulb of any type (say, H4 or 9006 or whatever other kind) that dependably works acceptably well in every/any headlamp designed to take that kind of bulb.
(Also, when acceptable retrofits do come into existence, they will not be sold under nonbrands through fly-by-night operators on Alibaba for $25/pair...these are clues...)
The SAE Lighting Committee has a task force working to define and describe the design and function parameters necessary to make a technically acceptable LED retrofit bulb, and the major-name brands are fielding early-version products, unfortunately following the same path of questionable ethics and legality that they've been following on LED retrofits for signal bulbs: not really legal, but there are loopholes in the way the regs are written that they sneak through. First line of products totally unsafe in any application (first Sylvania Zevo LED retrofits, with the plastic dome). Make money off of that, "for interior and off-road use only" [nudge-nudge, wink-wink], then put out a second line of products not really safe in a large number of applications, but they just pretend that problem doesn't exist (see
here for example).
There has never been a shortage of bogus claims for illegitimate products. First the maker or vendor makes the claims, then they're picked up and regurgitated -- and elaborated, like a fishing story where the fish gets bigger every time the story is told -- by eager enthusiasts who (1) want reality to be different than it is, and/or (2) want to feel validated in their purchase decisions, and/or (3) want to feel important, like dispensers of wisdom. This is modern "viral" marketing, and it's very effective. Truth and reality have nothing to do with it.
As far as the "retrofits" being discussed in the thread you saw: total nonstarter. There's a guy pushing them hard, claiming to be involved in aerospace engineering so he can't really discuss the details and all kinds of other cloak-and-dagger baloney; Dan Stern forwarded me a conversation he had with that guy, and the guy is just completely full of beans: really does not know even the basics of how headlamps work, but he's sure his guesses and assumptions are good enough. Claims to be an aerospace engineer but rants for paragraph after paragraph and page after page about how he has no use for people who talk about measurements and numbers, because they don't know what they're talking about in the real world (ummm...every real engineer I know spends most of their professional time dealing with measurements and numbers so as to create the things we have in the real world), etc.
He sent Stern samples of the retrofit you saw discussed in that thread. Stern tried them in a bunch of headlamps...with lousy results every time. As he related it to me: "At least the "aerospace engineer" was telling the truth, just not the way he thought: you don't need measurements to tell these are a complete nonstarter." He sent the samples on to me for a second set of eyes on 'em, and...yup, he's right; they're a total joke. There is no evidence of knowledgeable or informed engineering in these at all; there are very basic mistakes in their design and construction, and they don't even physically fit in a fair number of the headlamps they're supposedly designed for (kind of an important gate to pass before we even get to the pickier questions of whether they work). Those headlamps they fit in, they fail in.
Pictures: No. A picture will give a clue as to how bad a beam pattern might be, but won't inform as to how good it might be. Understandable details are described
here.