Personally, I seem to be incapable of respecting the comics (any of them) as canon. It's not because I don't like them (though I really, really don't), it's because they don't feel like the Buffyverse. Everything on the shows, no matter how much I dislike some of it, is automatically and unquestionably canon for me. But not the comics. The Buffyverse is live-action, with movement and music and sound and inflection and real actors all those other things only live-action has (and possibly books, if you have a vivid enough imagination, or animated series, if they're done well). It's three-dimensional. I can't look at this new story told in a silent, two-dimensional medium and properly connect it to the original shows (and it doesn't help that it wasn't told in a timely fashion). I just can't. That works out nicely because of the way I feel about the comics, but I think it would still be true if I liked them. Even though I know it's canon, I can't make myself see it as canon. To me, it's apocrypha for the medium alone.
And then there's the story, which does all kinds of ridiculous things that were never part of the show's lore, the characters' actions and motivations are often real head-scratchers, and there are so many storylines that don't really have a logical reason for occurring at all. Buffy robs banks? Kenny gets revenge on Dawn by...turning her into a giant, a centaur, and a doll? What? That makes no sense! And why on earth did she even date him in the first place? Xander is *friends* with Dracula? Warren is still alive despite being skinless? And a woman exists who isn't repulsed by him? Harmony managed to convince the world that vampires=good, Slayers=bad? Harmony?! Willow is going to live for hundreds of years? And then the Twilight arc blew the smoldering wreckage of my suspension of disbelief completely out of the water. Buffy has Superman-like superpowers? Angel has Superman-like superpowers? The *universe* has a plan? The universe is sentient?! Superpowered space sex creates baby universes? (Seriously, what the hell?!) Spike has a spaceship crewed by bugs? There's a little Seed that's the source of all magic in the world? The Seed is sentient too?! The Master came back? Etc., etc.
So, on the whole, it may officially be canon, but it *feels* like nothing more than one possible continuation of the story, though not a remotely probable one.