if u wan't people to like you, advertising what's bad about the competition won't really make people like u.
if u want investment to flow into your country, you don't really thrash talk your neighbouring countries.
why should it be different with religion?
if you show people that ur a positive person who has an excellent personality,
if u show the world that you offer the best tax breaks and facilities and amenities,
and if you show the best of what Islam can offer..
would it matter what the rest do?