The different tax treatment applies only to Proprietary Directors, meaning directors who own more than 16% of the company. It doesn't sound like you will fit that category.
Sybil
Do bear in mind that the rules governing PRSI class (A1 or S1) are applied using different criteria to the '15% rule' governing eligbility to employee tax credit.
Get specific professional advice on this and related issues before committing yourself to any change in status. Your employer's accountants/tax advisors may be able to assist.
Lorz, associate director is a fancy term for a senior manager in some financial companies. Unless you are becoming a non-exec director or own the holdings outlined above I imagine you will remain as an employee for tax purposes re salary.