Load-pull systems are very versatile characterization tools for RF power devices. The measurement results enable the quick design of highly efficient and linear power amplifiers without the need of a device model but also allow verification of developed device models under realistic stimuli. Currently available load-pull systems suffer of some shortcomings especially in terms of very high power handling, broadband modulation capability and differential mode operation. This paper provides a short introduction to advanced systems available within the TARGET Network of Excellence providing solutions to these needs.