Dan DeLave wrote:
New ones do not hurt as much if you happened to get hit by it. I would go with the newer one. You will have to put a strap or line through the back of the sail to be able to attach it to the boom. You do not use a shackle for this one.
I agree with Dan - the new boom is a lot safer by virtue of it's light weight and round profile. The main sheet loads in the vertical plane are not transmitted to the boom - it goes from a strap (or line) from the clew to the top of the main sheet system, passing on either side of the boom. There is a shackle connection from the end of the boom to the clew of the main - this is for the outhaul.
The boom is only seeing compressive loads from the outhaul and the horizontal vector of the main sheet. This is why the weight can be dropped so much.
There is one "trick" with the new boom - disconnecting it from the sail (e.g. when dropping the main). To get the loop/line over the back of the boom, lift the luff rope of the main out of the track below the slot where you get it started. This gives you enough slack in the foot of the main to get the loop over the end of the boom without standing on tip toes lifting the boom above your head, or having to disconnect the boom at the mast. One less ring ding to mess with when putting the boat to sleep for the night at a regatta.
P.S. I will get the pictures of the STX vs. ST main taken one of these days...