The new Mk. 3 from Nacra looks like a nice evolution and retains the very proven Infusion Mk. 2 hull shape in a potentially stiffer package.

As to epoxy, that's a complicated issue. I spent some time looking at the difference in material properties. Vinylester is actually stiffer than epoxy, but some epoxies have the advantage of higher elongation before failure and a slightly better fatigue life, but that also depends on what materials it is used with. For example, an S-glass Vinylester boat will be stiffer and have a higher fatigue life than a pure E-glass/epoxy build. One could even build an S-glass pre-preg vinylester boat and have a product on par with the Marstrom Tornado (which is an S-glass pre-preg nomex hull) due to the allowable weight margin.

The real gains on an F18 are made in the fabrication process and choice of paint over gelcoat. I don't know if Nacra have chosen a painted or gelcoated hull.
Paint alone can save 16+ lbs out of a pair of hulls, which is good for an extra layer of glass plus local reinforcements. Phantom were the first to realize this (and win a World Champion in 2012), Exploder followed suit with the Scoprion. Cirrus build a quality boat in France, they don't employ this trick but they make up for it in the fitout details and extremely beefy beam sections. Edge are similar in this regard as are Falcon.

Where does all that leave Nacra? They have switched Infusion production to the same facility that is building the N17 Mk. 2 so I expect the build quality to be on par with the other top builders and the fit out of the beams to be nicely done. The convertible trunks are a smart move with an eye towards the future. The new board position is also super proven on other F18's. I'm not sure what the new Pro-Grip looks like but the Pro grip on my Mk. 2 is of a high quality and very durable so I expect that to continue. Nacra probably have the best parts and support network in the U.S.

Hopefully this launch combined with the decksweeper generates some renewed interest in the F18 class here in the U.S as we look towards hosting the World Championship this fall in Sarasota.