Opinions? I personally really adore the look of this set, the proportions and overall look are all very well executed, in my opinion, and work well to compensate for the down-scale. The fact that the arms have any actual shoulder articulation is a god-send, and goes to show the skill of the designers behind the line. However, I am most amazed at how the designers managed to balance out a pretty wide plethora of colors so well (aside from a few blue pins).
As for your comment on the shoulder articulation, I am pretty sure that wouldn't work in the long run. If someone, preferably a kid, was to push the mech forward, the weight of the arms would've likely caused them to wobble back and, at said kid pushing the mech back, forth. You'd need to have the special stoppers that are present on the armpits of the actual model to be on both ends, most likely, limiting both sides of range and making the articulation practically useless.