Maybe a Diablosport or other type  of tuner will help you out. A lot of
tuners let you change the shift points. The factory settings  are preset
for a modest driver. Have you tried disconnecting your battery so that
your tranny relearns your driving habits?

Hello

I had a similiar problem on my '01 V6. I my case cleaning of the MAF sensor
helped a lot. I coudn't believe the difference. After that I almost felt it
too sensitive with kickdowns! :)
If you disassemble the strange air box containing the MAF, you should pay a
lot of attention to the neoprene gasket when putting things back together. I
don't understand, how Ford could design it that way. With time that seal
leaks unmetered air and dust into the system - I even considered filing the
gap with silicone sealant to make it 100% tight.

If you pull out the MAF sensor from its housing it may appear quite clean,
but slightest amount of dust on resistance wires makes lots of difference.
Use electronic solvent in a spray can (or brake parts cleaner) and spray it
liberally. Let it soak for a while, and then spray again. If some residue is
still there, use a corner of folded paper tissue to gently rub it off.
To remove the sensor you will need the security torx bit, but now I'm not
sure about the size. T27 maybe?

I wish you luck
Marcin