The Points Based System (PBS) is not designed to limit the number of people settling in the UK. Therefore it is completely unlike the Australian system.
According to Government figures, the PBS would have cut net immigration in 2007 by 8%, when a reduction of 75% is required to stop the UKs population hitting 70 million in 2028.
http://www.migrationwatchuk.org/BriefingPaper/document/162