I guess it depends entirely on what you’d like to achieve – i.e. do you want to trade or invest? Would you like to invest actively or once a month? Do you want to be able to trade any shares listed on the JSE?
Auto share invest allows you to invest in some of the listed shares on the JSE - although the number of shares itself is limited. There are also limits on when you can buy and there's a minimum investment amount of R500.00
Tax-free investments are available only for specific exchange traded funds (ETFs), there are no tax-free shares. It’s also important to note that there’s a difference between tax-free savings account and a tax-free investment account. A tax-free savings account (TFSA) is offered by Standard Bank while a tax-free investment account (TFIA) is offered by Standard Online Share Trading.
You should pick your platform based on your investment or trading needs.