First off let me say that the plastic quality and color matching on this modification set is actually quite good, as are the paint applications. Once installed, the modified parts have the desired effect of making CW OP look like the IDW version. That being said, the elongated thighs present an unique issue when it comes to alt mode; namely, the darned thing doesn't hold together. I'm also not a huge fan of the way the chest "halves" (more like 2/3 and 1/3) hook over the smoke stacks. Tabbing the new chest and ab pieces into place is starting to put stress marks on not only the new bits but also the original smoke stacks. The thighs and the fiddly bits attached to them make posing problematic in anything but the default stance. I haven't tried combining yet (mostly because the combined mode didn't impress me much originally) but I can see where the new thighs may cause issues there too.

While this upgrade kit has great visual appeal, in execution it's a really terrible upgrade kit. Nothing included in this kit will lock down properly when applied to the figure, and the truck mode will absolutely not hold together if you try to transform it thanks to problematic thigh parts. It makes a nice display piece, but it will always threaten to explode on you on a moment's notice.