Tachy is indeed Very Good.
She's got a Generations/Studio Series level of articulation - the only thing she could even be said to possibly be missing is an ab crunch, if anything. If I had to pick any negatives, its that she's very back heavy without her boots attached. Its too bad she doesn't have a way to hold any guns, either.
Very posable though, and a good hand-puzzle! There's no instructions in the original release(don't know if US versions get some) but I was able to work out her transformation fine, without any parts unexpectedly detaching(as her bappy paws gloves/car sides are designed to detached as part of the process). Figuring out where her feet went was probably what I had the most trouble with, though its obvious once you spot it. Also have to mention that rotating the handpaws making the claws slide in was a inspired touch to deal with that part of the transformation.
She also has good clearance and rolls well in car mode.
The original release cards have NFC chips embedded also(to be read by the Metal Breath roleplay toy), but not sure if the US ones have one? Curious to see what kaiju it generates in Ultra Kaiju Monster Rancher... *edit* apparently only the S1 bots had NFC cards in the Korean release, but the CHinese releases of the later bots may still have them.
Also interesting side note when comparing with Hasbro's offerings is her retail in Korea, after currency conversion, is the same as our Voyager prices. She's pretty big though - her box is practically the same size as Big Convoy's.