Motorola Droid :: Touchdown Vs Remote Web Access

Can someone please help me understand the advantage of using Touchdown to manage my corporate emails, calendar and contacts? We are running on Microsoft Exchange Server 2007 (on Small Business Server 2008). The phones that are using activesync in our office have to enter a password every time they are brought out of screen saver or sleep mode.This is very annoying and I don't want this. I am currently connecting via my company's Outlook remote web access, not directly to the server. No password entry required. So far, this is working for me. Updates to emails, contacts and calendar are immediate. Emails arrive on the phone typically before they appear in my Outlook.Now, what I am looking for in the way of improvements:

1.Adding a signature to my emails (required for FINRA and SEC compliance).
2. Fixing contacts so they are listed by last name. They are currently in first name order when viewed on the DROID (not in Outlook).
3.Ability to accept meeting invites this is a minor issue.