I'm a 4.0-4.5 player which recently returned to the courts after a 8-year absence. Got my IG Prestiges some weeks ago, as I played almost my whole life with the PC600s (sold

). Always liked the Prestiges, despite the not-so-low power, which I used to fix with a little lead.
Ok, so we all know that some grams in the hoop leads to power boost. But now that I string around 40 lbs - instead of the 60 lbs which I've always been used to -, the power increase was good enough for me! No lead necessary. (And I bought 4 packages of it!)
So, here's my question: If the goal is to increase power, and assuming you're happy with the frame's weight and stability,
is there any actual difference between lowering the tension or adding lead? Issues about different levels of control, maybe?