My favourite scan tool is the Ford IDS.... a touch spendy for the hobbyist or DIYer....
I'm not familiar with the Actron tool but I have heard many that enjoy AutoEnginuity... I will add that you need to check closely to find the price for what you want out of the tool. I understand that there are different "levels" and such.
Of course the ability to run the KOEO and KOER on demand tests is important. Accessing the data stream goes a long way to making life easier. Output state control (the ability to make the module command an actuator for test purposes) is also a desireable feature though I'm unsure if either tool will give you this.
Finally.... the ability to communicate with proprietary modules (ABS, instrument cluster, GEM, et al) is going to be important. None of these modules can be accessed without using a capable scan tool. And don't forget to make sure it can communicate on CAN networks...