So, here we go.
First, here's a fun pict of four of the seven Tachis. These are the three standard blues (and the one variant) I found here, here, here, and here.
|Four unique Tachikomas|
But enough about the Tachikomas (nifty as they are).
Here's the assembled build-a-figure (BAF) of the Arm suit (sometimes "ARM suit", thought I don't know of an acronym for it) -- basically, it's a heavily armored exoskeleton for military personnel.
|The Arm Suit Build-a-Figure (BAF)|
Oddly, this looks to be modeled after the Russian Dazhdbog Arm Suit, which was a successor to the GSDF Type 1 suits (which were the successor to the non-manned "slave" remote-controlled units). But I thought the Russian units were blue, and this guy is matte black (though I do seem to remember a drunken scuffle between a Tachi and a black Russian suit).
As far as the sculpt goes, it's a bit hit-and-miss. It's in scale, and the pieces are reasonably solid. However, the lower back wheels and gattling cannon don't rest on the ground like they should, which besides destroying the perception of functional design, makes the whole thing a bit unstable.
That's fine though -- collecting this set was all about the core toys -- the BAF was gravy.