Excellent... but check your mast compatibility anyway. RDM have different bend curves than SDM, much more in the bottom I think. You will keep your sail longer, and get more from it, with the proper mast (not necessarily a North). Your loft should be able to advise you.
Feeling sluggish and slow to plane is not uncommon in strong winds. Sometimes you can hardly sheet in and your board seems stuck upwind. Additionally, low speed suggests that your sail was maybe too flat (too much outhaul). I don't think it has anything to do with your boom. Raising it may help in moderate wind but many sailors would lower it in high wind anyway.
Last edited by Farlo; 28th April 2010 at 03:35 PM.