It comes out today and I will of course be watching it but the general consensus does seem to be that it's "boring".
To be honest, I don't think the Netflix Marvel shows have been infallible. I largely enjoyed Daredevil and found Jessica Jones to be compelling, mostly because of Killgrave. I didn't really connect with Luke Cage that much but definitely found redemption in it's soundtrack.
Of the four Defenders characters Iron Fist is by far my favourite and the one I've been most looking forward to. I wasn't that excited about Finn Jones or Scott Buck as showrunner but I've always been willing to give the benefit of the doubt. When the "white saviour" stuff started to happen I was firmly on the side of "you can do the character without that trope", because, like Luke Cage, some of the best Iron Fist stories have been about celebrating and examining Multi-culturalism and NOT Culturalism.
Mostly though, I was excited for a series that got deep into the lore and delved into stuff like the Immortal Weapons, the Seven Cities of Heaven. I was keen to see Yu-Ti and Shou-Lao and Davos; I liked the idea of a show that was going to do that stuff and blend street heroics and the occassional goofiness of the Heroes for Hire world. Even on a Netflix budget I figured we would get a show that was able to balance these things and celebrate the character and the many different cultures involved.
Perhaps because it was ostensibly the most ambitious of the four shows is why it has fallen so flat. There were a lot of things to get balanced and I was pretty confident Marvel could do it after the previous shows but it seems like they've gone for a shockingly ambitious-less approach, that not only ignores all the exciting bit of Danny Rand's story, but also seems to misunderstand the central conceit and charm of the character.
I don't know - I haven't watched it and I'll be spitting out reviews over the next week or so, I'm sure. I can say though that I can't remember the last time my expectations for something had plummeted so quickly.