The part of my brain that I can never quite keep from playing in other people's universes has speculated that the VF-25, VF-27, and so on, as/if they exist in UF, don't do so in the main arena of civilized space - they ended up descending from a batch of VF-2s that were along for the ride when the Prometheus misjumped itself out of history somewhere in the early Exile. It's not VF-25, it's VF-2-5, built by-and-for that lost WDF offshoot on Kharak.

But, uh, obviously this is not in any way accurate.

Anyway. As specialist or rival counterparts, both the Messiah and the Lucifer (I, too, haven't sat down to watch Delta yet) have real arguments for points where they're superior to the VF-1. The Messiah's companion Super and Full Armor FAST packs are head and shoulders above those available for the VF-1 in terms of firepower, durability, etc, and the Full Armor config in particular has a three-mode capability that the Valkyrie can't match. The downside there, of course, being that I'd be very surprised if you couldn't get two VF-1s with FAST packs for the price of a single Full Armor Messiah. The price of the base planes may be comparable, but I kind of suspect that their performance is, too, so much so that spare parts reserves etc are genuinely a deciding factor. The VF-25 being the better looking of the two just can't compete with that.

The Lucifer, meanwhile, has a hell of a party trick (Fighter-carried Class Omega?!), and the better g-canceling tech in the UFverse wipes out its big canon weak point, the need for full conversion cyborg pilots. OTOH, given what we see from All Feature programs in the real world, the price tag of a single VF-27 is probably substantially more than a -25 with both armor sets, making them too rare to waste on missions that don't involve the need to pull a reflex cannon out of your ass.

The VF-171, meanwhile, as much as I love its visual design and miss the days when government forces were allowed to at least pretend to be worthwhile, is blatantly a Quickscell product, with all that implies.

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Iä! Iä! Moe fthagn!