Alasdair,
Good point, I was being sloppy with my terminology. Thanks.

Cappio777,
I see your point that even a small change may be important if your aircraft already has a small static margin. My experience has been that crossing the region from statically stable to statically unstable is not like falling off a cliff. The aircraft still flies like an aircraft, it just requires more and more attention as the CG is moved aft (obviously at some point you won't be able to keep the poles in the left half-plane). I really doubt that you would notice much of a change in flying qualities for a shift in Neutral Point by a percent or two of the MAC (even if the aircraft went from statically stable to statically unstable as a result of the shift).