I looked at upgrading and quickly decided against it. Now I use a great outlook add-in called Avidian Prophet, it is not ACT but it works great with Outlook and provides most of the functionality from ACT in addition if you are an Outlook user it does not make any changes to Outlook.
I recommend you contact Avidian and discuss with the sales rep how you are currently using ACT and they will explain in great detail how Avidan will adapt to your workflow. They are brutally honest about what the software does, and they offer full 30 day no question asked guarantee.
I have been using Avidian for 6 weeks now and am yet to find a single bug...a great improvement over ACT.
Here is a link
http://avidian.com/
Don't worry I have no relation to these guys just a happy customer as it meets my needs.