Some of the mini-series we're talking about here are a little less robust, a bit flimsier or more delicate seeming, but to get these little gems to actually work, some concessions must be made to lightness of mechanism.
Yes, generally they do seem pretty well built, but I don't think they hold a candle to the solid construction of the Tarot engine for example, but then that is at a completely different order of magnitude for scale!