ashben re: open source: if that's important to you, great. To me, it is not. I already feel like there aren't enough hours in the day to do all the things that affect my bottom line. This may be part of the reason that MS products have a large following in corporate America.
If, however, you're in a situation where you need to add some special functionality that can't be bought, then I can definitely see the advantage to open source. And I'm sure also a good learning experience, just poking through the code.