Hotwires used to be lighter so they still have a reputation and some styling, that garner a higher price. Other than that, there's no reason for them to be more expensive. Enjoy the Neutrinos.

The reason Hotwires are more expensive is that they are hot forged and therefore more labor intensive to make. The end result is a carabiner with an I-Beam shape, and a larger size and gate opening, yet the same weight. If you have the money, the following draws would all be upgrades: (Gear/Rope) Hoodwire/Hotwire, Nitron/Hotwire, Oz/Hotwire.

That said, Neutrinos are great carabiners in general, and for racking, I think you made the right call. The color coding is convenient, and I actually prefer a smaller carabiner for racking, if only for the way they sit compactly on my gear loops. They're still pretty light, and very functional.