I know a guy that has got Kingpins on his 90, and finds them good, and would buy another set. infact he brought a set of four, and has just brought a spare now, £50 a corner has to be thought about.
All I can say is if you like them and like the price, go for it, find out for yourself, some people dont like remolds, some people will always buy the most expensive because of the label.
At the end of the day do labels bother you, do you like them, does it do the job in your case, and is it in your price range.
After seeing what my mate does with Kingpins on his 90 then I would have no problem looking at the next time I get a set of Play tyres, As I have just had an expensive incident on a tyre that I had only done about 200 miles on.
I have heard the agument that the walls are thinner ect, but at the end of the day that bit of re-bar will go through the tyre wall,