Georges - There are two ways to race with the Harken. The first is to just drop the top collar below the track feed. This allows you to do sail changes etc. and to tack to the deck,and you do not to remove the drum. This is what we do most of the time. However for the NOODs and the NA's we completely remove the drum because it looks better in pictures (-: and it keeps the lower 2 feet of the sail nice and true.
Dropping the collar takes about 30 seconds. Removing the drum takes about 30 minutes.
I have my racing sails cut as if I did not have a furler except my #2, that is what I keep on the furler. The North Loft in Salem made me a great #2 last year.
I personally do not think it hurts us any great amount. Yea I am sure there are times I might want a bit more headstay sag but I can tune the rig to get it close. I can still easily get 6"-8" of sag.
Three of us here have all North Sails from the guys in Salem and they are excellent with excellent service - highly recommend them.
North Loft - 978-745-1400 - Jack Slatery for Sails and Brad White or Steve Cruse for service.