Got another quirky one. The cruise in my Foz works, but after about a minute. So if I'm driving at 70 and engage cruise, let off the gas, it will slowly decelerate to about 40 and then VERY slowly accelerate up to the set point. If I try to adjust it up or down, it takes another minute to catch back up. All I've check thus far is cable tension, replaced the vacuum line, and lubed the cable.

I'm guessing the internal boot might have a tear which causes the vacuum required to pull the cable to take a longer time to build up. Or maybe the controlled is shot; the car has a lot of electrical quirks.

Somehow you are loosing vacuum in the system. Either there is a split in a vac line, but then you replaced that. Then,  there must be a tear in the vac unit itself. Easiest thing to do is to get one from a wrecking yard. I very much doubt there is any electrical problem.

Try to put a Vacuum pump on the hose and the cruise control unit and test it, then if it leaks go from the vacuum pump straight to the cruise control unit just to make sure it is not the new hose for some reason 

I'm actually having to lose the cruise on my OBS since the unit would interfere with the downpipe, so I'll toss that on and see if it fixes it.