Marketo Financial Mangement

We are planning to start using the MFM in Q1'15 and would like to hear more from the experienced hands :)

1. What exactly are you using the tool for? Just Budget planning or for the spend tracking as well?
2. Are you having a centralised approach for using the tool or does everyone who opens a PO have access to the tool for updating their own Budgets etcc..

Thanks!