From the waist down, I think that the ROTS Clone Pilot is a great figure and I'd actually go so far as to say that from the elbows down he's a great figure. The problem with the figure (from my perspective) is in the upper torso and head, which has very little useful articulation (none of the three pilots I have can even move their heads even a fraction of an inch) and what articulation it does have (shoulders) is difficult to utilize.
The shoulder articulation being the traditional (at least for SW) cut joint instead of a ball joint makes the elbow articulation very awkward because the arms are stuck pressed against his sides. While this is useful in him piloting the Gunship, the wider cockpit(s) of the ARC-170 would benefit from having a pilot who could "stretch" his arms to the controls on either side instead of just holding them straight ahead and flopping around when you happen to do a barrel roll. (Not that I would do anything like that mind you

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There's no excuse for the head though, which in my eyes is a step way backward to the quality of the POTF2 X-Wing Luke of 1995 in terms of detailing. They could have very easily solved the head articulation problem by slapping the head of the AT-TE Gunner on the Pilot, make a removable helmet, and be done with it. The thing that is getting me is that Hasbro told us all last year how they didn't have time to deal with new toys for that year's line (OTC) for the most part because they were so busy developing the ROTS line, and now they're putting out several toys that are based on pre-production artwork and missing the boat on the Clone color variants, even though they, according to their own words, spent ALL LAST YEAR developing the ROTS line and would have had plenty of time to make the necessary changes.
Making the Episode I Boss Nass so short or keeping the Geonosian Warrior in Saga without his pants are understandable, but with the proven sales records of Clones in various colors and knowing a full year in advance that there would be multiple colors of Clones (and having photos of them to go by) and not taking advantage of that? Something is a bit fishy, I think, or at the very least it's a huge

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It could've been done, and I'd take that over the odd laser tower accessory and whatever the hell that black thing he came with was
As much as I agree with you on the uselessness of that tower (HAY GUYS, LET'S USE AN OLD MOLD FOR NO REASON!) accessory to begin with, that huge arm does have a purpose (albeit a really sketchy one). The "claw" end of the arm has a small peg on the bottom of one of the claws that plugs into a small hole on the base (in that little slot) on the radar dish column. So, it's kind of a remote trigger for the dish that doesn't actually work, if you will.
Of course, this is all assumption on my part, but it's the only place that I could figure it would go after looking at the thing for the past few months. Hasbro just keeps on skimping on actually telling how this stuff works (I'm still trying to figure out what the base with R2-D2 "does" and what purpose the column with Jedi Kick Obi-Wan has). And I'm sure those of you who were actually able to find the Unleashed Aurra Sing at retail remember how much fun THAT base was to put together, even going by Hasbro's "wonderfully detailed" instructions.