I have been watching this discussion on approach speeds. First, the lad in the G-IV may have a fairly high calculated approach speed and will be configuring at or before the marker and holding the speed from there. Trying to reconfigure (in the case of an RV adding flaps) and slowing to a reasonable approach speed after breaking out of the weather can be a real sucker move. Going fast down the ILS then breaking out, trying to slow and adding flaps can cause an increase in altitude and, in the worst case, put you back into the clouds. In airliners we configured so that when the runway was in sight all you had to do was pull a little power off and land. It all depends on what is going to happen when you break out. If the weather is 1000 and 3 underneath, go for it, you have time to slow. Same if you know that your are going to face a circling approach once out of the clouds. But if you find yourself facing a 200 and 1/2 situation, slow down and take your time.
John Clark ATP, CFI
RV8 N18U "Sunshine"
KSBA