I like the feature in Pages '09 that lets you drag and drop a contact on a document and auto-fill all the contact info. Numbers and Pages both used to do this. It is nice because contacts can be shared across all my devices. For things like sales orders, I would use address for billing and a new field "work address" for shipping. It worked very nicely.
To be honest, I do not need access to all my contacts for this and could export from Contacts to another data base of some sort. Then there are lots of apps that would work and be confident of long-term support. An open source office suite, Google Docs, or MS Office might all work, but not any Apple product.
I like Apple for their robust OS and hardware, but they cannot be counted on for long-term software (or hardware) support. This is disappointing to me and most other professionals. For me, my computer and associated software are tools that must never fail. I don't have the time to keep changing how I do things and I must be able to work with old legacy documents. I have learned to make pdf backup versions of everything I send out, just in case the app that created it is discontinued. I have nearly 40 years of past documents with few losses. I have customers that have been ordering the same or similar things for over 20 years. Their loyalty is because I can service old machines I have built.