Since my mail is POP3 I can check it from virtually any computer. Verizon has a e-mail on the web site and there are other sites like Mail2web.com if I need to be on a computer. So the Outlook web access isn't a compelling feature for me.
As for the wireless sync. I agree it's a great feature and it's the only thing keeping me from 100% saying no. But I think in the long run I can force myself to sync every day if it's going to save me $20 per month.