CARA will not 'suggest' where to move your speakers but will select the optimum position within the range/area you specify. However, it is based on the information you enter into the system and not on real-world measurements. Also, it is based on powerful but incomplete analysis models. I think it is a great tool to use before room design and its value declines as more and more real-world constraints are imposed on it. There is a simpler and easier equivalent that is probably as useful in completed construction situations: RPG's Room Optimizer.
XTZ, otoh, is a measurement system that will tell you how the system is actually performing in your room. It will suggest filters for the room/loudspeaker variations below the critical frequency but it cannot suggest setup changes because it cannot know anything about your system except how it measures at the microphone. REW is similar but with more tools, as is GoldLine's EZTUNE. There are several others. These will all tell you what is wrong (or right) about the measured setup but leave it up to you to change that and see if things get better or worse.
Kal
XTZ, otoh, is a measurement system that will tell you how the system is actually performing in your room. It will suggest filters for the room/loudspeaker variations below the critical frequency but it cannot suggest setup changes because it cannot know anything about your system except how it measures at the microphone. REW is similar but with more tools, as is GoldLine's EZTUNE. There are several others. These will all tell you what is wrong (or right) about the measured setup but leave it up to you to change that and see if things get better or worse.
Kal