I'm going to say that there are times when Kyon seems
too snarky to me; when the snark is so heavy laden that it contributes to the "unreliable narrator" effect that some of us here have pointed out.
Beyond that... I really don't see what's cool about always being negative.
Seriously.
Sure, a fair number of his comments and jokes are funny, but he goes overboard at times too, I think.
I'd much rather hang out with somebody upbeat like Haruhi. All in all...