I have found Droid's Exchange support to be on the pretty weak side thus far. Using the built in mail app, my Exchange account stops syncing every now and then and the account has to be deleted and reinstalled to fix it.
I started using Touchdown Exchange for Android and while it is a better/more feature rich app... it does not do Notes and it also needs to be reinstalled now and then and, also... when adding a Contact from phone call history... the phone does not give you the option to add to your Exchange or Touchdown account... just the Gmail or phone lists.
I am not griping... I dig the phone, but it does have a lot of growing up to do. At this point, I am probably going to switch back to the native Exchange app so adding contacts from phone calls works correctly. Touchdown is awesome, no question about it... but the adding contacts glitch is a deal killer for me. Right now I have TD working but I have to go to the menu and tell it to sync to send and receive instead of automatic push and send.
Guess I will be reinstalling the stupid account more often... maybe I need to learn something about either one of them but so far I am not too happy with Exchange support.
Still the best open source-(ish) mobile computer/phone combo available IMO