the lucasi shaft is totally different than predator's design. the predator has a hollow bore in the tip end of the shaft with a short 6/10" sleeved, capped ferrule made with some lightweight material called maxlite (formerly titan). the lucasi design has no hollow sections, the secret is in the ferrule tenon, which is a straight thru design. the maple tenon is turned pretty thin, about 3/16". then a sleeve of lightweight wood (i believe it is basswood) is put over that, bringing the "tenon" now to the typical 5/16". then over this is put the ferrule, which is also a lightweight material like predator, called XTC. The ferrule is 7/8" in length on the normal flexpoints, and about 1/2" on the slims.
the predator is lower deflection than the lucasi, as the hollow bore is more effective in removing weight from the shaft. lucasi hits real nice though, and the LD is still pretty good.
hope this helps