I have been using ACT for almost 2 years now in our office. it was working very nice but from month im facing some problems. Since we often need to work from outside, we have a setup with some ports forwarded to access inside machines. Since about 1 month, it has stopped working. Checking the IP on the router, it seems an internal IP is being assigned.
Someone mentioned they are NATing all connections to some machine which has public IP. The most frustrating part is that they will make such changes that are likely to affect so many customers without any announcement email any kind of intimations. They are best in connection speed but they should give proper customers support too. Overall its good to use but need to develop their customer support.