The actual build is great, it's got great posablility, looks awesome, and is very accurate to source material. However the connections aren't very strong when transforming. I'd say the set is pretty worth it, the only issue is the transformation process.
This set is the set for all transformers fans. Of course there is the flaws of the 1/2 gap on the face and the no knee joint situation, but if you know how to do it, you can easily get that done. That's what I did (see the images below) absolutely perfect for you giant robots display
One of my favorite sets it combines my love of Lego and of Transformers. Optimus being able to transform is great. Only downside is that fact he can fall apart if your a little to rough with him.