questions re speed mods for cherokees

In a fit of insanity, I'm considering adding some speed mods to my
160hp cherokee 140.

For those that have Knots-2-U, LoPresti, or Laminarflow speed mods,
such as wing root seals, aileron seals, stabilator seals, flap hinge
fairings, I have some questions.

1) How have they stood up over time?

2) Were the installation times reasonable or hopelessly optimistic?

3) Did you feel any mods weren't particularly useful?

4) Do they make preflights and/or annual inspections more difficult?

Thanks

--
Bob Noel
no one likes an educated mule