Speaker setup experts please?

The Cardas is a good start, also there are the rules of 1/3 and 1/5 which minimize modal contributions. We have quite a bit of information on our site, including a link to a pretty neat simulator. There is the RPG optimizer (which we also sell). It works well for rectangular rooms, but if you have a strange shaped room then the Cara software (we also sell) is a better choice.

For Wilson MAXX-2's, you should have a Wilson dealer set them up for you. Wilson has a specific methodology for setting up their speakers for which all dealers are trained.

there are a million rules, the Cardas works very well IMO
TAS's HP likes the rules of thirds, for instance if your room is 15 x 21 put the speakers 5 feet apart and 7 feet out into the room - 5 is 1/3 the width and 7 is 1/3 the length. This worked very well when I had Maggie 1.6s but they were so far out it was not practicle.

Rules of thumb are general guidelines. Your own trial and error experiments will prove what works and what doesn't. Proportional rules only help at specific frequencies so that no matter what you do, there will always be other frequencies harmed.

An approach I've found more beneficial is to take care of first reflections. Most all speakers need "breathing room"—3-5 feet from the front wall, and at least 2-3 feet from the side walls. This space helps sufficiently delay the first reflections. Psychoacoustic mechanisms of the brain can then separate the direct sound from the reflected sound. Delaying these reflections also reduce their volume, often doing more good than random room treatments. It should improve imaging, clarity, and usually give you a more dimensional soundstage.

If you can afford Wilsons you can afford to have them set up by a dealer.