How would SRS benefit a person who plans to invest and take it out before 62 year old?

The 5% penalty for early withdrawal is gonna negate any accrued tax benefits from deferred payments

Firstly, if you intend to take out before Age 62, its NOT RECOMMENDED. Unless your taxed now really damn high.

If you withdraw before age 62, you will need to pay 5% fee for the withdrawal amount and will be taxed 100% of the withdrawal amount.

This means that your 'profits' from investing SRS must be more than 5% and at the point of withdrawal, your income must be significantly lower than before. (Maybe due to retrenchment, etc)

Else, the normal way is basically wait till age 62 then withdraw the amount in tranches. If you already retired at age 62, the best way to withdraw with lowest tax is to divide the total amount in SRS by 10 years and withdraw the amount consistently. (So you are taxed at the lowest amount possible)

If you are still working at age 62, it will depend on your income bracket to see how much to withdraw to maximise tax savings. And also depends on your retirement plans.