Some have reported double faces in the selection, but nothing like that in my box.
Paint at the base of the arm for the fusion cannon: you need to insert the weapon without sliding against the base, but directly applying pressure on the tabs. No paint chipping occurs after a number of attempts.

Overall: no paint defects, solid articulation.
The real issue is the silencer: even clipping it on with extreme caution, it chipped away some paint. Looking at it more closely, you can see the tracks in the silencer: they're not smooth, they're slightly raised and have 'cutting' edges, the real culprits for the paint chipping.

I restored the colouring with a sharpie, and took care of the cause: removed 4 screws and took out the attachment inside. The attachment is what clips to the gun's nozzle (making it harder to remove it later, which can cause the breakage) and pushes its outer side against the non-smooth parts of the silencer. So I removed the culprit (below), with the result of a silencer which is slightly less stable but with no paint chipping issues whatsoever.

The riskiest part of the transformation (which I imagine is what has lead to the legs breaking in some photos circulating online) is the bringing together of the hips to form the gun's handle: behind the hip joint, there is a screw that needs loosening a little, to ease the swinging of the parts.
There is indeed a neck, you just need to rotate the head upwards.
There are some delicate passage in the transformation from gun to robot, too, where a handy tool (screwdriver or small lever) can come in useful, as you take the same steps backwards. Transformed carefully a number of times, and no issues here.
Despite these necessary cautions, I can only welcome Megs in my home; the engineering, aesthetics, and figure overall are extremely pleasing. ^^