The Student Direct Stream (SDS) has a higher acceptance rate than the regular (non-SDS) stream. However this is largely a result of selection bias.
It’s less that the SDS drives success. It’s more that those who were likely to be successful went for SDS. The strength of the candidate matters more than the stream they opt for.
This is why a lot of candidates who go for the SDS end up getting rejected. They become complacent and put together a weak application.
A good Cover Letter, Education Strategy, Financial Support Letter, and comprehensive Financial Documentation are key to resubmitting an application that will be approved.