I have a similar setup with Avast and MB Pro, but I had some issues which caused me to just use MB Pro on demand. Browser speed was affected and I think it may be something to do with the website blocking feature interfering with the web shield…possibly. Will play more when I can find the time.

Re firewalls, I use and highly recommend PrivateFireWall. Yes it is a bit chatty at first but if a user prefers they can simply put in training mode overall for 7 days, or alternatively train each application alert assuming that you are sure your PC is already clean and that you are been alerted by a valid application. All firewalls with HIPS are similar in this respect of having many alerts at the beginning, but PFW is nice with the training mode.

Comodo was a nightmare and I stopped using it after several years of hoping that they would improve it.

The smartest firewall with HIPS that I have used is Kaspersky as part of the Suite. It is a great suite if you have a recent (2 years) PC. I have a laptop 18 months old and noticed some drag with KIS.