I had the original Cybertron Prime a while ago, but I eventually sold it (it was a mistake). When this was announced, I jumped on it, hoping to capture the same feeling as the original. It's really a different animal entirely, aside from similarity in looks. Galaxy Upgrade Optimus Prime is a great toy, just don't expect it to be a replacement for the original. It also kills me that the original came out 16 years ago as of this writing.
In robot mode, with the guns, he stands 7 inches tall, making him Leader class. He's got an imposing silhouette with the wide wingspan. It does make display with other transformers a bit difficult.
Articulation is about what you'd expect from a big chunky boy like him. He's got the usual swivel ankles that allows for a wide stance.
Two guns are store on either side of the legs and can be held in either hand.
The silver gun can be held on its own, or in combination with one of the black guns.
The large cannons on the back can be swung around and under to act as additional weaponry, and you can attach the other weapons to various connection points around the body. The end result is one armored motherf*cker.
The Upgrade armor can be removed to reveal a non-powered up Prime.
Prime can transform into the cab of the vehicle. The whole transformation is kind of a mess and not very intuitive with lots of parts swapping. When it's together it feels very haphazard.
This is one that just stays in robot mode. It's just not fun to transform.