Charlie,
I have several hundred hours in the A-4. Yes, the slats are aerodynamically controled and work pretty well except when they come out unsymetricaly. This can be from just mis-rigged, dirt or grit in the slat track. The biggest problem comes up when you are in manuvering flight. Due to uneven air loads and g loads on the wings the slats will come out asymetricly. If you are being really aggressive this can lead to a slat departure (from controled flight) if you don't ease the pull. This can make normal formation flying a little tricky as well since the flght lead and wingman can have their slats comeing out at slightly different speeds. Sometimes as a wingman when you feel the slats start out a little stick wiggle will get them out a little smoother and evenly. This is why when the Blue Angles flew the A-4 there slats were locked up. They did not have any switch in the cockpit to extend them they were essently welded in the retracted position.

I suspect the above discussion also applies to the F4D Skyray as well and may have had even more problems since it was designed earlier.

The T-39 Saberliner has aerodynamically actuated leading edge slats on the wing. I have flown this plane as well. It may show up at an air show near you. Ask one of the pilots there to demonstarte this feature to you.

The little cat fight earlier on is entertaining. For the record the 727 has both Leading edge Slats as well as Leading Edge Flaps. The flaps are inboard and they will droop down within about a minute after hydraulic power is removed. You can see them on the ramp with them down. The slats have screw jacks to push them out.

For my $.02. If the slats on a model cost me one pound I would take the weight savings and reduced complexity.

Sparky