And they differ by price range and customer type. At the range of up to say $400 (anecdotal, not precise), I guess they are valued for their quality, reliability, durability, price / performance ratio... In terms of Swiss competition, there is largely only Swatch in the same price range, which mostly does not attract the same customer type - little cross shopping there IMHO.
When you get to Grand Seiko territory, things change drastically. The average buyer in the price range has no clue about it (yet) and the signaling potential is negligible for the peer group.
At the same time most watch aficionados will either love them, or at the very least respect them (even if grudgingly). That's the great thing about them. For most people they are invisible but the ones with whom it is fun discussing watches will mostly both notice them and want to talk about them.
In my recent experience there has been pretty much a uniform response by such people. Talking about the brand gets them mildly interested but not enough to check it out. When they see mine (chances of seeing one in the wild in Europe are still between slim and remote) they all want to have one / know where the nearest AD is.
Had a discussion like this only yesterday with a very patriotic Swiss colleague. Owner of several Rolexes, APs, GPs, Breitlings, a Chopard and a VC and fairly taken with the subject and informed about it. He's been one of the rare people to have noticed and commented on my LUCs in the past. But the GS was the only watch he asked me to take off and show him in detail and the appreciation was palpable.
Will that transfer to the general public buying watches in the €2.000 - €10.000 price range? Unlikely in the short run but that's part of the appeal.