Green tea kit kats actually run a wide gamut.
Just amongst the kitkats produced in Jpn with Jpnese packaging, there have been different generations and different variations.
A decade or so ago, I tried a Kyoto-only one that was a collaboration btwn Kitkat and a famous green tea producer and it blew me away.
But it had been a long time since I'd actually had a decent maccha kitkat. This even includes the special Ito Kyuemon maccha kitkat, whose maccha flavor was watered down.
Recently I decided to give it another try. I got the one called "Maccha no chikara," and I feel like they finally got it right again. I have not seen that one in Seattle/Vancouver.