Most notably in terms of new tooling, the panels on the undersides of Powermaster Optimus Prime's forearms feature slots under the fists, which allow the guns to tab in and be held much more stably than with Ultra Magnus. And due to the amount of empty space in the cab area in vehicle mode, Powermaster Prime can fully transform without the need to remove his head.
The Transformers Energon figure pen is based on Optimus Prime in his standard Energon body. About the size of a scout class toy, he transforms from truck mode to robot mode almost identically to his mainline toys, apart from the fact that his feet contain the pen and cannot bend. It's really hard to write with, and almost impossible to pose, even though it has full arm articulation. Amusingly, this figure can position itself to transform into his super robot mode (by flipping his helmet on, opening his chest and flipping his hands in), but because there are no versions of the Prime Force drones in this scale, it's impossible to complete him.
This release of Buster Optimus Prime was susceptible to a paint scraping issue on the silver painted slide-out barrel of his blaster. This problem was fixed for the DOTM Re-release by relocating the silver paint app from the barrel to the inside wall of an exposed gas tank that had been previously left as unpainted grey plastic. The black paint app on the barrel was left unchanged.
The toy that would ultimately end up as the original Optimus Prime toy was originally released in August 1983 as No.17 Battle Convoy from Takara's Diaclone Car Robo toyline in Japan. In 1984, Joustra released their own version (still with Diaclone sticker on the trailer) as part of their Diaclone line in Europe, either simply called Truck (according to the pack-in catalog) or Diaclone (in the pack-in comic). It's possible that GiG also released a version called Camion Convoy as part of their Trasformer line in Italy, but to this day no packaged sample has surfaced.
This is a redeco of Ultimate Optimus Prime. While Prime himself only features a red grill, the trailer has been extensively redecoed, with an ornate golden Chinese dragon being painted on the trailer panels, and the various gray parts of the trailer panels, armor, and cannon being replaced by blue, red, gold, and burgundy. The toy was released as a "Year of the Dragon" Special Edition in 2012, since the Chinese Zodiac sign for that year is the Dragon.
Partially constructed of die-cast metal, this small three inch figurine of Optimus Prime has a CGI-accurate sculpt compared to the larger toys, owing to the fact it does not need to transform at all. He is sculpted with his Ion Blaster in his right fist, and is articulated at the neck, shoulders and waist. He comes with a small movie-style Autobot sigil display stand.
The lowest priced toys in the Armada line were three-packs of Mini-Cons. Each larger price point consisted of an Autobot or Decepticon who came with a Mini-Con partner. Mini-Cons could be used to unlock a variety of features on each larger robot, such as firing weapons, electronic lights and sounds, or alternate modes. Some three-pack Mini-Cons combined into other forms or had additional features. According to the storyline, Mini-Cons also enhanced the power of other Transformers, giving incentive to collect as many of them as possible.