From what I could tell you get access to all base classes. However, when you make modifications to the system, you use their customization manager to create the subclassed item. At that point the system has registered that you are no longer using their base class for that part of the application and instead instatiates your subclassed item. The nice part of this is that when you do an upgrade, they only upgrade the baseclass. Which will upgrade your subclass without requiring you to "port the mods".

Years ago, when you upgraded SBT you had to take all your modification and move them to the upgraded PRG's or forms. Now, if you follow their modification guidelines, you no longer have the problem.

The only place this doesn't work is on the menu structure. If you add an item to one fo their menus instead of putting the item in the custom menu option, the upgrade will over-write your menu change and you will have to recreate that menu change. But that is a small price to pay for the other gains.

Alan Wyne
IS Manager
Rollpak Corp