I found this article very useful in setting up Gmail Exchange sync for my Contacts. Before I had Mail, Calendar and Notes synced with Gmail and found it limiting that I couldn’t also sync Contacts.

This is in many ways great, but the one annoying bit is that data fields that I've taken for granted for years and years and have been using in Outlook / on all phones (including the iPhone) disappear. So far I've only seen one ("Other number") but I wouldn't be surprised if there are more.

It's annoying as I have multiple details under one contact, and a good few of my contacts have the Other number field in use. Sure, I can manually change these to "Fax work" or something else that Gmail supports, but it would be much easier if Google supported what is by all accounts a standard.

Overall it is a winner however, and it's good to know everything is now synced with Google, though I only use Exchange for Contacts. Mail, Calendar and Notes are synced using the vanilla Gmail option as I want my Notes, want editable drafts in Mail, and don't understand the benefit of syncing Calendar with Exchange when the Gmail option works perfectly.