Not at all, I find PrivateFirewall one of the best ones to work with Avast. At the beginning you will find it intrusive only with software that are not digitally signed so I recomend to launch all your programs after installing it and give permission thru the firewall and above all to check the ones that you trust, after that you will see that it just does its work.

One of the things that I like from this Firewall is that it is always improving.

Check my signature, I have been using it for more than one year since I discovered it here in this froum without problems. I’m sure you will have a nice internet experience with it if you install it.