A customer would find it useful to be able to set restrictions by teams of users. For example you may have a sales manager who needs to just see a certain set of account manager's accounts as they're the sales manager for that area. Currently you can only set restrictions based on the companies that they're the account manager for or just see all data within the CRM.
We've also now added restrictions by Territory. This provides broader categorisation and restriction than was previously available through using just Account Managers. Now the customers of multiple account managers (who work within the same team) can be assigned to a given territory (e.g. the "North Team") and all members of that team can see all accounts in that Territory.
It is possible to implement more variations/options (almost unlimited) for record restrictions in the Advanced CRM Subscription.