If you feel comfortable in the flight suit then wear one. Just dont wear the gold braid on the shoulders.
Dont wear one in the vintage aircraft (even though the fuel tank is just above my knees), but do wear one for aeros. and a chute and a lid for my sweede.
just had a suit made by <A HREF="http://www.flightsuits.com" TARGET="_blank">www.flightsuits.com</A>
having been a badly burn in an accident i would recommend some nomex