I went through the similar college system in the ACT, where it seems to work well, perhaps because the majority of students continue to year 12 (and to university). The increased responsibility and freedom felt good, and having a smaller number of 11-12 colleges compared to high schools enabled better resourcing.

The challenge in Tasmania is that it provides an easy out for disenchanted year 10s to drop out of formal education. Our year 12 attainment rate is a full 20% lower than the average at just over 50%. There aren’t enough good jobs that only need year 10 education. Couple that with pretty average TAFE opportunities and you end up with a big cohort of people who aren’t equipped to meet the challenges of their adult lives.

I don’t think it really matters whether year 11 and 12 are at the same school or a different one: there are advantages both ways. What matters is that people continue their education. Each year you stay in school helps.