I was asked just this week whether I'd had a hair transplant - by someone who didn't know me before I had a system. It was a bit awkward, but I could understand why he asked: he is losing hair quickly at age 30 and is planning to have a hair transplant this year. I felt bad lying to him because I did say that I'd had a hair transplant (rather than the truth that I wear a system) and I think he believed me. I then warned him about the reality of hair transplants and that results are very variable.
The problem with systems in many cases is that they are just too good. Most people at a certain age (such in in my 40s) just would not have such nice hair - regardless of the density, it is the quality/shine/length too that sometime look too good. I love the look, but maybe it isn't realistic beyond a certain age. And I tend to go for lower density and 15% grey.
I'm sure many other people have noticed that I wear, especially my first 2 systems which were pretty awful in comparison to my more recent ones. But no one had said anything to me ... just the occasional glance. Though now, with this improved system, I reckon people look at the hair and wonder how come I have a full head!
@jimlad I agree, concealer was much worse. The 2nd glances eventually made me move to a system even quicker.
I think you’ve nailed it there, they look “too good”. I transitioned without anyone knowing but the responses I got and still get is how amazing “my” hair looks. And I think that is what could catch someone out, like @Noah said when the guy spoke to him “looks too perfect”.
Almost need the systems to be more flawed aesthetically to be more realistic if that is what the wearer wants over it looking amazing.