I don't totally mind that flame piece on Ikir and Tahu being Tr. Red and Tr. Yellow, mainly because it's usually used as a flame, and thus under no obligation to match other types of parts like armor and bones. Protector of Jungle even managed to make the Tr. Blue and Tr. Yellow flames work despite his main color being green! On Tahu and Ikir I'm more bothered by how the orange color of the crystal blades doesn't really approximate any of the other solid or transparent colors in their designs. Knowing that an actual transparent color for that piece wouldn't be possible, I'd probably have just colored them Bright Red, which is a closer match to Tr. Flu. Reddish Orange in my opinion than Bright Orange is.

My problem with the Piece of Unification being used as armor on Tahu has nothing to do with its texture, it's about how scrawny it makes his upper legs. Most of those other highly-textured CCBS parts you mentioned either weren't used as armor or were considerably bulkier, so didn't create that same problem. I already had mixed feelings about how lanky the 2015 version's upper legs were, and now the 2016 version feels even lankier (with no armor even approaching the hip joint). If his legs were not so long it might've worked fine. Certainly it doesn't look nearly so awkward on Kopaka's lower legs, which are two modules shorter than Tahu's upper legs.

I'm also bothered by just how many textures Tahu has in his design, because it just makes him look busy, as opposed to the 2015 version which used a select few textures consistently throughout, and thus felt a lot more unified. But this isn't the fault of any one piece. I wish it WERE, because then fixing it would be a lot easier — just remove the problem piece and, if necessary, put a more fitting piece in its place. But as it is, it's much tougher to decide which parts should stay and which should go.

As for the new torso shell, to me it just feels excessive. We're talking 21 pistons on one piece. That's more than the Toa Mata had on their entire bodies. And unlike the Toa Mata's pistons, many of these pistons on the new torso shell are in places where it doesn't make any sense for a point of articulation to be implied. Pistons on other CCBS pieces have been used more sparingly, which helps them to feel at least somewhat purposeful instead of just slapped on as meaningless decoration.

I don't especially mind Tahu's colors, though more red wouldn't hurt. The Dark Azur accents are brilliant and I wish he had more of them. Like Gali's Bright Orange parts, the contrast with the set's main colors really makes the entire color scheme "pop". It's the same reason the Bohrok's Krana colors and eye colors really added so much to their color schemes.

Are Tahu's shoulders really wider than an Inika torso? According to the instructions the shoulders should be eleven modules, exactly the same width as an Inika torso, just as the 2015 version's shoulders were. Unless you're counting all the way from the edge of the armor rather than just measuring from the joint...

Overall, I have warmed up some to the new Tahu after seeing more pictures of him, but like most of the new Toa, really, I don't think he's nearly as refined-looking as the 2015 version.

I have warmed up some to the new Tahu

Oh, you! XD