I use the business version of Google Apps to run my email service. Why? Less hassle and cheaper. Plus, save's my servers from being overloaded with spam. $100 a year compared to $1,000 is a big difference. I'd rather just stick with the lower price for the better quality.You offer hosting. Why are you using a free email service still? Run your own email server.
http://www.google.com/apps/intl/en/business/features.htmlWhere do you get those numbers from? Last time I knew, postfix and qmail were both free?
I use my Gmail on Xbox live, Windows Messenger, and other Windows-related sites.I use both, both have their advantages & disadvantages. I personally prefer Hotmail because I use MSN and I also have it fully integrated into my WP7, and of-course use it for Zune, Xbox Live etc etc.
I also use Google for more business orientated email, but don't use Google Apps as of yet.