The VF-31 is prettier, better engineered...and yeah, has so much shiny new stuff crammed into it that it would have a similar price tag. It doesn't have a full Armor Pack like the 25 does, but its Super pack is very similar to that of the 25. The OTHER party trick it has is the aforementioned weapons pod, which is mission configurable. The EW specialist in Delta has a folding radome that can stow for launch or high speed maneuvering and then deploy upon arrival, and one episode they feature sound-and-light pods mounted similar to the ones used by Sound Force in Macross 7. While these replace the rifle the VF-31 carries, it also has twin arm-mounted Vulcan cannons, so it isn't completely disarmed. In addition, the weapons pod is deployable in all three modes.
So yeah, shinier, but probably very damn expensive

>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 SV-262 is similar. It has a hella powerful cannon, and is manuverable as hell in fighter mode, has a full VR cockpit like the VF-19 (the canopy isn't even transparent, so lose power and goodbye, vision...) and is being flown by a race of almost-supermen (they are stronger, quicker reflexes, better senses, etc...but only live to their mid-30s, and still mature at the same relative rate as humans, so a teenagers is MIDDLE AGED) so it seems to be even stronger than it actually is, but its a completely new transformation, is much more mechanically complicated, the transformation limits the amount of fastpack equipment it can mount (primarily leg packs and deployable wing-tip drones), and overall is the VF-21 or 27 all over again. The quality of the pilots is the strongest element of the mech.

>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.
>

The 171 is the first-generation-RGM-79 of the Macross universe.

-D-