I loved mandatory voting. I found it shocking that it was optional to vote when I moved to other countries. If it's the norm in the country you're from, it's quite surprising that the majority of countries in the world have it be optional.
The reason that I am a huge fan of mandatory voting is because of the way that it changes campaigning. I had never heard of a “get out the vote” campaign before I left Australia. Rather than a campaign being about why you should come out and vote and risking the appeal to very populist or extreme positions that can attract real fanatics on certain issues to come out and vote, everybody is already going to come out and vote. The campaigning becomes a lot more about the issues and the policies.
I had never seen such personality-based politics, until I really started looking at the U.K., the U.S., and Canada and these places that have the first-past-the-post system with optional voting. In Australia, my experience was always much more campaigning about the issues. I worked on issue-based election campaigns there.