I have been using my dual 2.0 G5 Powermac every day since I bought it in September of 2005. I use it for video editing and DVD authoring, and it has yet to give me a single problem.
I would love to upgrade to a Mac Pro, but they're so stupid expensive that I can't justify it until my G5 starts to falter (or until I can't put any more software on it due to the non-Intel chip, which is starting to become the issue).
I would love to upgrade to a Mac Pro, but they're so stupid expensive that I can't justify it until my G5 starts to falter (or until I can't put any more software on it due to the non-Intel chip, which is starting to become the issue).