[Shotimes] Strange ATX behavior

[sho2go]

My fairly new '95 ATX doesn't seem to shift into OD until 10-15 miles/minutes
after driving somewhat sedately down the freeway, first time of the day.  The
engine temp has long since stabilized, outside air temp ~70, what controls
this final shift?  Does it take this long for the tranny to come to temp?
Also, the kickdown at lower speeds (40-60) seems to leave a lot to be desired,
first a pause, then high engine revs, then a kick in the butt.  I still have 3
mos. left on my ext. warranty; is it time to use it, or will Ford tell me this
is normal?
Mike