First off, let me say that if you haven't bought a Classics Universe Prime/Magnus/Nemesis, buy one now. Drop what you are doing, go to Greenhills, visit Rich Toys, Wasabi Toys, or Great Toys and buy one.
This is, quite simply, the the best mold/design for Prime (barring the Masterpiece since lets face, how many of us have 5-10k to drop on a single toy?) and it's what really got me started on collecting transformers again. Both the robot and the truck modes look like they scream "Kick-ass-super-leader-bot!" and the articulation can only be matched by the aforementioned Masterpiece or maybe the Revoltech TF line.
To give you an idea how poseable he is, heres a list (note that some of the joints are combinations that result from his transform design so don't fall under normal classifications): neck turns left right, arms go foward and out, elbows up and down, waist goes right and left, hip joints go back and forth and out, knees go back and forth, and there's even an "ankle joint" if you want to stick him in a flying pose. It's not the Marvel Legends range, but you can stick him in demn near any pose that a Transformer really needs to be in.
I won't discuss the transformation process itself. Suffice it to say, it's one of the most satisfying that I've come across and results in very little kibble in either mode (unless you count his doors in robot form, but I call them sheilds and leave it at that). In addition to the great design and engineering, they integrated his weapons into the form. His smokestacks becomes a nice looking double-barrelled rifle, and his the top of his cab (the "wind vane") becomes an odd-looking cannon.
Next to your other Transformers Classics, Prime/Ultra Magnus looks very impressive. He towers over the normal Deluxe class figures by something like two heads. Bumblebee or the newer Autobots in the latest waves look great next to their leader, though the Decepticon Seekers look a tad small in comparison. Then, I'm not as much a stickler for scale as some.
Now the best part, the Fans Project upgrade. Let's face it; Ultra Magnus is just a plain old re-paint of the Prime mold, as is the Nemesis. Fans Project went and gave him a trailer that converted to armor, just like his G1 counterpart. If you had the original G1 figure (raises hand), you're gonna want this kit.
If you do want one, run to Greenhills again to Great Toys (they're running out so move it) and fork over a cool 3.9k. It's an exclusive, collectors market add-on so you'd expect it to be expensive.They come in a blind box, but when you buy it at Great Toys, you can open it to inspect it before you leave the store. So far, I haven't heard any complaints from other collectors, though mine had some minor paint splotches. They were all in places where you couldn't see them anyway, so no worries. It's made of pretty sturdy plastic, but you need to be careful since some pieces are a tight fight and might snap if you use too much force.
The trailer mode is very nicely designed, considering it's a third-party add on. It looks like it was made as a piece with the cab, and has virtually no kibble. All the armor parts are used in the trailer and fit tightly, so you won't have any little pieces lying around to lose. It'll fit on any of the three figures that use this mold, but really, the paint scheme dictates you stick it on Magnus and not Prime or Nemesis (though you can probably reserve the black Shadow Commander set for Nemesis by the time you read this). Unlike the G1 toy, you can't actually fit anything inside the trailer as it's full of robo parts hidden from view, but can't have everything at this scale.
Again, I won't describe the transform, you can look that up online, but it is complex and will take some time. There's no "auto-morph" features so get yourself a glass of water if you're one of those guys who makes the "cha-chee-chi-cho-chu" noises while transforming him (raises hand). I prefer to learn transforms on my own without the instructions, but for those of you who don't want to take the chance with your 4 grand, there are a nice set of instructions in comic book form. A great touch from the producers. Suffice to say, the transform on this toy is totally satisfying, but not overly complicated; the best place for a Transformer to be.
When he's all put together, he stands about three or four heads taller than the Classics Prime and looks very reminiscent of the G1 design. The posts on his shoulders, the red, white, and blue colors, the great big boots and the antennae on his head. It's all there and it's all beautiful. There is a loss in articulation, mainly because the armor is bulky, but you'll be able to put him in some heroic poses. No high kicks though (I always figured Mags as a brawler anyway).
He also looks great against the other transformers from his line, towering over the Seekers and Bumblebee, and matching the new Universe 2.0 figures nicely. Again, I'm not too particular about size in relation to other toys, so the disparity between him and some of the Decepticons isn't something that bothers me. As long as he's bigger than the other Autobots, we're kewl.
The biggest gripe I have about the kit is the size of the "gun". There are some different ways you can put it on his arm, but the sheer size of it means that there is no way he can hold the thing up. It's like a huge block that masses about half his body and extends out ridiculously far. Maybe it was just a extra part they wanted a use for, but I'm much more satisfied using his own weaponry.
What ever accessories you give him, he will look like the bad@$$ mofo he should look like, able to kick Decepticon butt all night and still harangue the new recuits in the morning. If you have the extra scratch, I suggest you run out the door, flag down a taxi, and get to Great Toys as quick as you can.
Here's hoping that Fans Project makes a new trailer for the Classics version of Optimus Prime, with a functioning Combat Deck and a Roller!