It's a very useful tool, but someone once said a fool with a tool is still a fool. Please don't take that the wrong way, my point is that you still have to use some common sense when using this program--it's not an automated "here's what you need to do with your room" kind of program. I have been able to make disasterous room that measured well on the CARA--I was trying to do this by the way and see if I could trick the program. I was able to, but if you use some basic acoustical principles along with this program it will get you on your way to a better listening environment much faster than you could do by ears alone. However, in the end to get the best results you should do the modelling, then acoustical measurements, and then final tuning by ear. It's too complex to do all of this by ear--it would take most decades to accomplish these things by ear.
As to CARA's complexity. It's not so much the detail in measuring--although this is important (garbage in garbage out), it's really the way they deal with 3 D objects. For example a slopped ceiling means you have to build a 3D slopped object and hang it from a flat ceiling that is at the crest of the ceiling. Not the most intuitive way of doing things, but the CARA help file is EXCELLENT! And even something that is not intuitive is pretty easy to accomplish if you read the help section.
As to CARA's complexity. It's not so much the detail in measuring--although this is important (garbage in garbage out), it's really the way they deal with 3 D objects. For example a slopped ceiling means you have to build a 3D slopped object and hang it from a flat ceiling that is at the crest of the ceiling. Not the most intuitive way of doing things, but the CARA help file is EXCELLENT! And even something that is not intuitive is pretty easy to accomplish if you read the help section.