I am by no means an expert, but I was wondering why we didn't have variable sweep wings in civilian aviation. So I took a look at some designs.
Turns out during some initial testing as the wings sweep back, center of pressure moves back as well, and they lost some planes that were 'nose heavy'.
Hence when you look at your variable sweep planes these days, they have that fixed wing portion that extrudes away from the fuselage. It creates lift at a fixed point, keeping center of pressure at a fixed point. Extended from that are the smaller variable sweep portions, that being out so far don't seem to affect center of pressure so much as that portion of the wing doesn't create as much lift(less camber/less lifting area/less induced drag)
I gather they worked on a variable sweep wing that as it swept back, the attachment point to the wing, moved forward, to keep the center of pressure in a flyable place.
Seems the moving wing thing might be for the history books for a couple of reasons.
New wing technology seems to have made the 'lower and higher limits' of the wing larger...basically more efficient.
I suspect also that the computer, training, hydraulics, weight, etc...might add up to being more of a pain, when the engines are getting more efficient to get the speed/range advantages.
In civilian world a variable sweep wing would be great to increase range and speed at altitude, but I don't see it happening right now. Considering the SJ30 is probably the most efficient corporate jet on the market and that company is pretty much sunk, it tells you that technology moves slow in the civilian world.