Over the years I've used both setups.
That meaning, like you have now Speedy, with Avast anti virus and OP FWpro.
As well being my versions have always had the Firewall module (not installed) I have run the Avast Firewall (instead of OP) and found it quite fine, yes and quiet.
I used OP FW because at the time, I was not as comfortable with Avast FW in terms of tweaking stuff and OP had 'File/Folder Lock'.