I am a material science chemist and using impedance method to characterise the dielectric properties of some novel materials by paralel plate capasitor method. As you can imagine there are a few brands who produce decent instruments for these kind of measurements. But, with the developing technology it is possible to observe similar readings with AD-IA combination compared to old 100K$ instruments. I am also an electronic hobbiest and bought an AD2 just for testing the idea and compared the result with an instrument. On that time the IA board was not available but, the readings was very similar to a commercial instrument. Anyway, now with the IA option it is more easy to make measurements. But, the biggest problem with the current setup non-autoranging the resistor values. Sure, this can be overwhelmed by making some coding. However, the IA add-on board is very complex to modding, i.e. the realys have laching function which can not be released by applying reverse control logics. Furthermore, there are also several other lack of hardware functions, such as high output current, limited input impedance of the CH1/CH2 althoug the input opamps has very high imput impedance etc. Hence, I think in the first instance the IA board should have auto ranging function. This can be done by the DIGILENT engineers, which is out of my experience and I do not have time to understand communication protocol and commands for communication of AD2 with computer. The second development again can be done by digilent which can be a decent IA board (IA2). This second release should have higher WG current to measure lower impedances and high input impedance function to read high impedances (There is a video on You-Tube mentioning a basic board ).
I think these add-ons can increase the importance of AD and Digilent which did a great job upto now. Best wishes