[Sarakiro]

It is mostly a matter of convenience. I managed to get my hands on one, so it will likely be cheaper to find some extra used ones than it is to buy more motors with gearing options. It also doesn't hurt that their output is relatively high torque and lower speed than various other options, which again- I would likely end up spending full price for anyway.

It is also easier to design for a product that I already have one of.

Thanks,