Peter, I don't think you can compare the Alpacka Scout to the Kokopelli Hornet. The Scout is a tiny boat that's not suitable for regular sized people. I haven't poured over the specs, but I believe a closer comparison is the Alpacka CuriYak, which is $715. So with the Kokopelli Hornet ($475) you save $240.
The Hornet is 6oz heavier than the CuriYak, but we can't really argue about ounces without knowing why there is a difference (ie. money doesn't buy weight savings with a raft because the materials are seemingly the same). The weight always comes from somewhere, so the Hornet may be larger or more durable or something else. We'd need to identify those weight differences to decide whether or not they are worth it.
I'd rather have the proven CuriYak, but the money saved is quite significant.
Sort of on this topic, Alpacka's pricing is out of whack. The Scout was always a way better deal than the regular boats, which is why many people asked for a larger Scout, or the ability to buy a spray deck for a Scout. Alpacka refuses to put decks on them, but did relent with a larger Scout (called the CuriYak) but the price went way up for this boat that costs virtually the same to build (note that all sizes of the regular boats are the same price, yet a larger Scout is +$170). I believe Alpacka has now raised the price of the Scout as well (IIRC it was ~$400 1-2 years ago). I guess I shouldn't complain too much because in reality the Scout was just a smokin deal and now that time seems to have past.