I agree with SafeSurf on this.
I am a big fan of Revo and use it all the time.
In the case of an anti-virus program, or even some firewalls,
you really do wish to use the removal tools offered for them
if they exist. The removal tools are designed to target specific
areas that the program uses, and in fact Revo may miss.
Proper removal is one way to ensure that you will not have any conflicts
with future set ups.