Overall, I think the design is well done. They did a great job capturing the design of WALL-E. Having the plant is a nice touch. It always amazes me how people can use LEGO to construct things that look very close to the real thing.
One note is the design of the head. The swivel is rather loose and it doesn't stay in one place. LEGO has come up with a new design for the swivel. It includes some additional pieces and new instructions. If you bought the set early on, you can find the instructions and some details here. I e-mailed LEGO customer service to ask about how I can get the new pieces and instructions. I will do another post once I get an answer. In the meantime, from reading the various LEGO fan sites, it looks like if you buy WALL-E now, you will get the upgraded design. If anyone has purchased it recently, let me know.
Should you buy this set? In my opinion a lot depends on whether you are a fan of WALL-E or not. Those that don't know the movie or didn't enjoy it may not enjoy having this set. As a fan of the movie, I thought it was great and am glad I got it. The price is about on par with other sets on a price per piece ratio so not too bad. The build is very creative and if you want to take WALL-E apart, there are some great pieces to build other designs with. I'm sure a lot could be done with the tracks. Another bonus to the design, there was no sticker book. All of the pieces that would have stickers are printed onto the parts themselves.
If you got this set and have built it, please let us know what you think in the comments area. I'm curious to hear what other fans have thought.