Does anybody know how much more a comptip weighs than the equivalent section of aluminum mast that was on a Hobie originally?

And, does anybody know: If you have two Hobie 18's, one with a comptip and one with the original, solid aluminum mast, and if both masts are well sealed and do not contain water, which of the boats is most likely to turtle (or which will turtle the fastest) when they capsize in identical sea and wind conditions? And which is the hardest to right?