If your age and citizenship gives you the chance to vote Yes to AV in the upcoming UK referendum, you should do take it.
Not because it's more or less fair, nor because it will advantage some party over another, nor because lots of money is at stake. Nor even because the 'No' campaign is so mendaciously lacking in transparency about its true motivations.
You should vote yes because our democratic system is outdated and broken in all sorts of ways, and a 'No' vote at this referendum will be relentlessly exploited by anyone who wants everything to stay just the way it is.
Think the civil service is broken? A 'no' vote will be used to prevent reform there. Think the Lords should be reformed? A 'no' vote will be used to stifle that too. Want to see MPs given really different career incentives, to generate better patterns of behaviour? 'No' thanks. Want to see major democratic innovations like participatory budgetting given real scale, and real teeth? 'No' means 'no' there too.
The last really major upgrade to the way our democracy works was the Parliament Act, way back in 1911. If it takes another 100 years to to adjust to the reality of a post-deferential, ICT mediated world, I really can't see our country doing very well.