I generally accept DS9 as canon, though not many of the elements I dislike about TNG that carried over, such as the depiction of Klingons. I’m not sure if I accept Jadzia’s death and Ezri Dax’s existence as canon.
The TNG depiction of Klingons is just a slight variation on the depiction of Klingons in The Motion Picture, The Search for Spock, and The Undiscovered Country. (Except they no longer have pink blood in the 24th century I guess, and the honor culture thing gets cranked up to 11.)
I’d say the TNG Klingons are flanderized versions of the TOS film Klingons. Also TUC had the most well-rounded depiction of the Klingons.
TNG Klingons can be fantastic, but I dislike their relative lack of depth as a culture. But that’s more an inherent flaw of TNG’s writing of cultures than anything specific to the Klingons. DS9 Klingons are a little better, especially once Martok becomes a regular.