lars888888
The CS 2.4 is easier to drive by far and easier to set up and impliment into your room. They are the sweet spot of the Thiel line up.
The CS5i need more attentiion to set up and require big power to drive with authority. They are big speakers. The bass is effortless regardless of how low you go.
I have both and do not remember the last time I listened to the CS2.4.