Multi-site implementation question

My objective for is to provide a SaaS solution to customers, with various marketing features built around Woocommerce for their stores.
My question is re: the multi-site model for this: Should I network enable components like Woocommerce for common code efficiency, as I will be running many sites, or given each customer will have their own store/data etc., should it be activated locally per site?
thanks, Neil.