"Is it compatible with my AMPro 1.x system?"

Yes.  AMPro received only minor changes to its front-end security system (which is a good thing, since you want to hear that a security system was made right the first time).  Most of AMPro's improvements and enhancements centered around making AMPro easy to administer, especially for large and diverse user groups. 

Only one minor modification to one of the AMPro database tables will be necessary.  The change is a minor but handy one:  User records now have a long text field available so you can write free-form notes on a user in the new user editor.  If you like you can disable this feature fairly easily and your existing AMPro database set will work immediately.

"How Will I Upgrade My Installation?"

If you have altered the AMPro templates, you will of course have to deal with that yourself, but a stock system can be upgraded by

1. Unzip the files to a location under your web root.  Run /install/index.cfm and choose "Upgrade" to upgrade your existing installation.  The next screen will explain whats about to happen to your database (one blank field will be added to one table).  Run the upgrader.
2. Look at the AMPro2 /Application.cfm and compare it to the original.  Port over any changes you see (There are only a few.  What you need to concentrate on is porting over your existing settings without making errors).
3. For public, protected areas, swap in the folders containing AMPro's includes and modules for the new system (your existing calls from your CF templates protected by AMPro do not need any changes).
4. Swap in the new AMPro admin area in its entirety.

If you use tiers, the tier-checker's bechavior has been altered to make it more flexible.  However, the two previous tier-checking methods have been preserved for backward compatibility.  Instructions on how to keep the old method are described in the upgrader itself.