Hi guy's, been a long time
Regarding rotate feeling light, this is mostly an XP issue (at least in XP11 that i knew well). In short, the 737 has a supercritical airfoil (NASA term, or "aft loaded" airfoil as Boeing calls it). One of the differences between conventional and aft loaded airfoils is (as the name implies) that the aft loaded airfoils have the center of pressure further aft. Meaning also the center of lift is further aft than on a conventional airfoil.
XP does not model this very well, and as far as I know has its center of lift at the 1/4 chord. So this means XP airliners have their center of lift too far in front which cause problems in the transition phase between ground and flight. Should be a fairly simple fix for Austin. There are some temporary "hacks" one can do, but it's a can of worms...
Good to see the old girl in the XP12 skies - great work Jan and Tom