It's an interesting question FOS has presented us with this Friday. Typical shades of gray from the old thinker.
Methinks the response cannot be generalized but must be responded to in whatever context it is used so I'll try it several times and see where it leads.
Two folks approach me. They take a look at my mulit-X sized frame and person A says Hey shack - I see you are somewhat circumferentially challenged. Person B simply sas Wow shack - you are fat. While both are true, A is not negative whereas B certainly is. Now which is more honest? B is clearly negative and I'd have to say more honest. As in B used the brutally honest approach. There's a reason that phrase is BRUTALLY honest. Now there's a time and place for both approaches - if A was beginning a dialogue in which je/she wanted to convince me to lose a few Xs that was the correct approach. B would simply engender a sarcastic retort from me along the lines of "That's a blinding flash of the obvious - so what?"
Now if we take the challenge to politics I'd say there is no way negative is more honest simply because virtually anything can be spun is any direction and in today's state of political dysfunction , both sides (luckily we are a 2-party system - India would make my head spin ala the Exorcist) adopted postures that seemingly say "the other side are a bunch of frickin idiots that are destroying the country and ignoring the constitution" Since they say that about everything it certainly is not honest. Frankly anyone that doesn't take his political commentary from a minimum of 3 sources is doing themselves and the rest of us a disservice if they are pontificating. Relying on Fox News is as stupid as relying on MSNBC imho.
Now when it comes to selling, I'd say negative is typically more honest. Ever hear the phrase "sell the sizzle"? That's salesman speak for accentuate the positives, eliminate the negatives. The error of omission. No way can that be considered more honest than simply stating ALL of the facts. Caveat emptor comes from there. :)
I'll leave it to you to decide if the following little ditty is negative or positive - personally I see both sides expressed throughout
There are numerous other examples that can be cited regarding today's topic. Check out the other LBCers for their takes. Perhaps even FOS will pick this topic to jump back into the fray with us.