Automap has Sonar support. If you ask me:
Automap Pro:
* easy to install
* work with sonar functions out of the box
* map plug-ins in much more intuitive way then ACT
Automap Cons:
* wrapping some plug-ins can be problematic
* managing wrapped plug-ins can be problematic
* for Sonar control you get what it allows to control, in general that cover basic needs but it is not extandable
* can not wrap ProChannel
ACT Pro:
* Sonar native, no plug-in wrapping required
* Can control big range of functions, configurable
ACT Cons:
* can be tricky to setup
* mapping range from buggy to impossible (but there is 3d party tool which helps)
* limited number of hardware controls or other limitations (when using with stock plug-ins)
For future information about ACT, see my signature.
For problems with Automap search the Internet
Automap on one of my computers is in some crazy state and I have not found any fix . It works after (re)installation till next reboot, but than some functions are no longer available... That is just one example