The legs are probably the best part of the kit, they didn't need a lot of work. But that didn't stop me. ;) The only major problems were foot articulation and proportions. The foot only had a small amount of lateral rotation, preventing the feet from sitting flat with the legs spread in cool poses. And the grey part on top of the feet was too small as compared to the line art.
Lateral foot movement was pretty easily fixed with a new joint system made from plastic sheet and some extra polycaps. I ended up with something like 6 points of artuculation in just the ankle! This allows the foot to move from side to side when rotating, giving more clearance for a wider range of motion. It's also quite solid, and is sturdier than a ball joint would have been.
The grey part on top of the foot was simple to enlarge. First I used styrene sheet to build new crossections, and attached them to the kit part. I filled them in with Bondo, then sanded the part smooth.
I used the "Bondo squish" technique to get the new part to fit on the foot. First I used a routing bit in my Dremel to route out a section large enough to accomodate the new part. Then I filled the routed area with Bondo (backed by styrene sheet for support), covered the new top piece with mold release (actually dish soap), and squished it in to the Bondo while it was still soft.
This left me with a recessed area that fit the new piece perfectly. Then I just sanded the gooped out putty flush with the surface. The Bondo did come loose (it doesn't stick to styrene very well), so I superglued it back into place. The picture below shows a comparison between the original and new feet.
That about does it for the legs. Next up, greeblies and nurnies.