Paying by means other than direct debit produces some issues. These could be:
Payments made by bank transfer/standing order have to be manually processed by the club so you may get invoice reminders for invoices that you have paid for but the club hasn't processed.
Standing orders are prone to over/under paying i.e. if subs are adjusted members will need to adjust the standing order so payments match invoices otherwise it may be that a member unwittingly pays more/less.