I have 4 graphene infused products, 2 from 303, and from the Turtle Wax Hybrid Solutions range. From memory I paid full for 1 of them, the others were all discounted.
The first I got was 303 Graphene Nano Spray Coating. It has a dark tint to the liquid, and does darken the paint. It did offer protection, but I can't remember what it was like for longevity. I know the darkening effect lasts at least a year, I could see it coming off the white paint on the FJs roof when I last polished it. I downgraded it's use to wheels the last time I used it, and even then I had to change the sprayer, the one it came with clogged up and was no functional. I'm pretty sure I won't using what's left, unless I use it on the lawnmower.
The second was Inside Job from TWHS. It's Ceramic +Graphene, and a cleaner as well. I like this product. The main reason I got it was all my other interior dressings would streak when they got wet, which is a problem on the FJs doors, the big plastic door skins get wet every time you open the door when it's raining. Is it the ceramic, graphene, or something else that stops the streaking? Don't know, don't care, I like the scent, and it cleans well. Will I get it again, maybe, but there's a couple of other products recommended on here I want to try, Cockpit and Pilot, there seems to be a theme here.
The third was TWHS Graphene Infused Wax, bought for $10 on clearance. It's a white liquid, so I applied it on the FJs paint as an LSP over the top of NV Lustre and Jet that was applied 6+ months before. It's had a couple of washes since it was applied almost 2 months ago, it seems to holding up ok. I'll wash it again soon and se how it's holding up. I may end up just using it on the wheels.
Most recent was the 303 Graphene Trim Coating, once again, heavily discounted. I only applied this a couple of weeks ago, but we have had some rain, and there hasn't been any streaking, and it's sill beading up on the trim nicely. One interesting thing I haven't seen before, I drove through some muddy water yesterday, and where the muddy water hit inside the wheel arch that had been treated, it beaded up and dried. So there's dried muddy water spots, something I haven't seen before, usually the muddy water sheets and dries completely brown. I guess water off the tyres removed whatever trim coating is in there pretty quickly, but not this stuff so far.
Not disagreeing with anything said above, Graphene is definitely a marketing hype word, did I fall for it, a little bit, but curiosity about new products is natural, and occasionally you find a gem.