Too low in my opinion. I think a basic principle is that you have lived a life outside of school and in the world of work before you vote. Obviously nowadays most haven't actually left education at 16 but there is a hell of a lot of living done in the years 16-18.
I also have concerns, as I think it's very open to parental influence at that age.
Also creates inconsistencies with other parts of the law. If a 17 year old is too young to face trial for a murder as they are deemed a child, then why are they capable of making informed decisions about politics, society, the economy etc.
Don't see any need to change it