My DaVinci Jr is actually
really reliable. There was a learning curve, but, the printer is designed with being kid-friendly in mind (it's not for kids, but it's designed knowing they're going to be around).
It's easy to use, safe (only the extruder tip gets hot/no heated bed) and uses non-toxic PLA plastic.
It puts out decent quality, but, under no circumstance, does it put out even
Hero Clix quality figures (99% of the time). It can do some pretty amazing prints (like print-in-place hinges). It printed a number of
these fairly well for my Infinite Weirdos game.