RichardH, I don't use the Optimus with a Gmail account at all. What I mean is that although I have a Gmail account set up just because they want you to, I have nothing in there ... no email, no calendar, no contacts, nothing.
What I do have is Outlook 2003 on my PC where I keep everything. Mail Contacts, Tasks, Notes ...
Before I switched form WinMo 6.1, I did a lot of research on syncing. I found this software called CompanionLink. It knows how to sync between Outlook (most flavors) on the PC and the Android. It syncs contacts calendar, tasks and notes. In my case, I only sync calendar and contacts. It works pretty much like ActiveSync does with WinMo. Actually, it works better than ActiveSync as it's a little easier to control and customize what gets synced. Now there is a funky extra step involved. This sync program $39 after the free trial requires a free companion product from the same company called Deja Office which has its own calendar, contacts, notes and tasks. When you connect the Android phone to the PC (via USB or other means, like WiFi) Companionlink syncs between Outlook on the PC and the components of Deja Office, then syncs with the built in Contacts and Calendar of Android. This works seamlessly, between the three components (Outlook, Deja Office and Android native Contacts and Calendar). I happen to like the Contacts app in Android the best, so that's what I use all the time. If I add a contact on the phone, it gets synced automatically to the Deja Office contacts, then when I connect to the PC, it syncs Outlook. Same with Calendar entries.
So, overall, I have been pretty much able to duplicate my setup that I had with the WinMo 6.1 phone I had. That was a Palm Treo 800w which I would've hung on to but the issues it had with battery (multiple tries) - power consumption and unpredictability of how the battery would behave made me abandon it.
I understand that the Optimus has the ability to connect to Exchange for corporate email, but I have no idea how that works, as I don't use it.
One other bit about CompanionLink ... they also have the ability to sync with other PIM type systems like Act, Lotus Notes, etc. that may be used in corporate environments.
And finally, No I don't work for CompanionLink. I was just happy I discovered them during my research.
I hope this helps.
Rob