I'm never impressed by any company, political group or in fact any one who's best shot is:-

"I have nothing of merit to say about myself so to make me look good I'll ridicule my competitor"

Not getting into a PC/Mac debate this goes across the board.

I'll have more time for any salesman who comes to me and says ... "Yes competitor's product XYZ indeed has merit, the company that I represent has similar products with equal features but may I point out some areas in which we excel"

That to me shows respect.

If your kids started to bad mouth their playmates would you let that go? Would you encourage them with ... "yeah the more you make them look small the bigger you'll appear to be" ?

Or would you rather hear them reply .. "But that's what the man on TV did and you just laughed"

ouch!