Most all of my equipment is Airtronics and I have created some habits that help me keep things straight while using "old" and "Z" connectors and these are something you'll have to create yourself when you have the "old" Airtronics burden.

I have 12 black, 3 blue "Z" Airtronics receiver's and 1 Futaba. Any common servo will plug into an old Airtronics receiver (black and gold) but as RCKen stated the wires are crossed. You have to get a $3.00 adapter for each servo and battery pack, or simply switch the red and black wires making sure the black wire is in the middle with the red on the outside, which is what I do. If this isn't done, especially with the battery pack several things will start smoking, you can trust ME on that one. I even have planes with old Airtronics servos and new "Z" style servos mixed in the same receiver with no problems.

As for your original question,

I can't speak for Spektrum but with any Futaba, Hitec, JR, Airtronics "Z" (blue) receivers , I have used all of the big 4's servos with no problems, and even mixed brands in the same receiver. Using the old style Airtronics plug is too much of a pain though because the plug is too fat with the 3 tabs on it to fit in the outlet on the receiver. I have found cutting the tabs off to be too troublesome and sloppy. It's easier to cut and solder a new style plug onto it paying close attention to the wire positions, or better yet keep them for the old receiver and get new servos for the rest.

The charge leads for the different styles is another thing you have to keep on your toes about too. Just make sure you you have an old style plug from an old style receiver and you can't plug the new style female into it.

I hope this helped....

Jeff