Disable Anti-spam in Exchange 2010

HI,
I've been using the Anti-spam functions in Exchange 2010 for a few years and they work fairly well. However, we are going to install a third party spam solution (GFI MailEssentials). I've used GFI before on an old Exchange 2003 server and it worked well.

I'm assuming leaving on the Anti-spam functions built into Ex2010 isn't a good idea, so I want to disable them. I know how to deleted them using the supplied scripts from Microsoft,  but if possible I wanted to keep them installed in case I find that I don't like GFI MailEssentials.

Thanks,

Mike