To have the choice between proprietary software packages, is being able to choose your master. Freedom means not having a master. And in the area of computing, freedom means not using proprietary software.
My own personal dream is that the majority of the web runs on open source software.
I might seem biased, but I use Evernote every day. It came to me through my readers, who I'd asked for software recommendations via Twitter and Facebook. For seemingly every function, the answer was 'Man, you have to use Evernote.'
I want to avoid locking people into solutions that work only with Postfix. People should have a choice in what software they want to use with Postfix, be it anti-virus or otherwise.
It didn't make a lot of sense for us to be doing Lotus Notes implementations.
Success for open source is when the term 'open source' becomes a non-factor in the decision making process, when people hear about Linux and compare it to Windows NT, and they compare it on the feature set and don't have much of an excuse not to use it.
Linux people do what they do because they hate Microsoft.
Production-wise, I've always stuck with Ableton Live and there's really no reason to switch to something else at this point.