The Formula Project Gundam F91 can be considered one of the most enduring masterpieces that stemmed from a Gundam series. It boasted a sleek, unique design that is complemented by a rich story that gave birth to another longstanding Gundam classic (Crossbone), securing the F91's place in the annals of Gundam history. Therefore, it comes to no surprise that a Metal Build version of the venerable mobile suit would prove immensely popular.
And it is.
The Master Grade 1/100 Gundam F91 broke new ground in terms of model kit engineering, gimmicks, and scale, being the first MG kit to use the miniaturised proportions of the F91 time period. According to in-universe lore, scaled-down mobile suits were first devised and tested during the Laplace events (i.e Unicorn Gundam) in the form of the D-50C Loto: a special operations use variable mobile suit developed by the Strategic Naval Research Institute (SNRI), which subsequently used the data collected to create the high performance F91 and its subsequent variants.
Ostensibly, smaller mobile suits are harder to shoot down. If you are in the gunner seat of a Salamis-class Federation cruiser, you would likely aim for a larger target, taking into account the chaos that is raging around you. Further developing this train of thought, SNRI further miniaturised mobile suit reactors to fit into a compressed frame, resulting in mobile suits that are roughly a third smaller than its earlier UC counterparts. After decades of warfare, mobile suit tactics have undergone a paradigm shift, with an emphasis on maintaining a cache of top quality, high performance machines as opposed to fielding large numbers of disposable ones (although these are still used for a variety of purposes like base defence).
The Metal Build F91 presents a distinctive change from its Master Grade cousin. Firstly, it's significantly taller, bringing it closer to the classic mobile suit height, although it's still smaller than its Metal Build brethren. All over the frame, there are plenty of redesigned features, and the whole machine is designed to invoke imagery of a Formula One race car, from the sharpened chest, polished limbs and of course the spoiler (with an advertisement no less) on the top of the backpack. The F91 is also the first Metal Build to use delicate and fantastic photoetched parts, reminiscent of the grilles and vents of high performance combustion engines.
Although the new mobile suit frame is now smaller, it does not scrimp on features and weaponry. Thanks to modern advancements in mobile suit technology, the F91's output is noticeably higher than older Gundam-type machines, with a clear cut improvement in maneuverability and agility. In the right hands, the F91 is able to perform delicate movements and evade all manner of weaponry, conserving its own ammunition until it is able to secure a one-hit-kill.
The F91 is packed with armament. From the regular handheld beam rifle and massive beam launcher which is essentially a giant warship-killing shotgun, the F91 is also armed with a large variety of built-in weapon systems from head vulcans to machine cannons and also the terrifying Variable Speed Beam Rifle (VSBR).
A formidable and versatile weapon, the VSBR can be seen as the deus ex machina of the F91 series. A beam cannon at its core, the VSBR is uniquely deadly in its variable modes: a wider beam for greater raw damage or a narrower beam to pierce even beam shields. Powered directly by the F91's fusion reactor, the VSBRs remain operational as long as the F91 is still functioning, and is able to fire more shots than the F91's handheld armament combined. In fact, the VSBR is such a masterpiece of mobile suit engineering that it is eventually put into mass production, and even after a ten-year development gap, was still lethal enough to pierce the Crossbone Gundam X1's Anti-Beam Cloak with a single shot. The VSBRs on the Metal Build F91 have undergone a radical design change: from the simple, full-shaped design of old to a heavily-angled and faceted weapon that now features heat radiating fins at the ends of the weapon, a logical technical inclusion considering the sheer amount of heat that the VSBRs emit.
The Metal Build F91 is a beautiful Universal Century inclusion to the Metal Build line of high end collectibles. If this is a sign of things to come, the prospect for future Universal Century Metal Builds - or just Metal Builds in general - is very, very encouraging.