A brief overview is in order, before we focus on the individual characteristics of each technology and how they perform. TN is the oldest of the LCD technologies and it stands for twisted nematic.
I've had an Apple 23" Cinema Display since about 2003/4. (I no longer use a Mac, if that's relevant.) I'm looking to go dual-monitor. Am I going to notice or care if I buy a TN screen and make it my ...