In the book that I have, The grumman X-29 by Bill Gunston, There is a lot of good info. In one section it has the following statement-

Without the canard the X-29 would be neutrally stable at subsonic speeds; with the canard fitted it is perhaps the most unstable aircraft ever flown with instability as extreme as 35 percent at low speeds. This condition has the happy result of making neutrally stable at mach numbers over about 1.2, which puts equal loads on the wing and canard and thus gives minimum trim drag.
Would the high speed stability have something to do with the CG issue that paul mentioned? It sounds like at low speeds the cg is farther back on the main wing to make it more menurverable and at high speeds things like thrust angle and wing incidence make up for the CG. I hould like to understand a little more about this plane before I get too much invested. Right now I am working on a 16" wingspan EDP50 powered model to work on CG placement. The bare airframe with no electronics will be around 2 ounces so it should survive alot of CG glide tests. Im not looking for a 3D plane when Im done just a decent flying scale plane.
Any input is appreciated.
Nick