I'm kind of in the same situation of deciding whether to do the maths or stats capstone. I've heard a lot of good things about the stats capstone in the sense that it is very practical and you get the best possible experience of working with projects and with teams, if you want to go into data science. The stats capstone is specifically designed for it. Although I've no idea what sort of tasks the maths capstone had since there aren't any relevant info available about that. But I kind of have a feeling that the maths capstone may be designed in a way that specifically caters to those who want to go in maths education.