File Auditing and Permissions Reporting Solutions

I have executives and auditors who regularly require reports of who has access to what (NTFS permissions and AD group membership for other systems). Currently, we do this with a combination of powershell scripts which export to CSV, and then we pretty things up in Excel. This works OK, but is VERY time consuming.

Has anyone used any decent network file/permissions auditing tools, which can provide fairly nice looking executive reports? We really only need fairly basic reports, like who has access to a particular directory (usually a couple AD groups), and then who's in said groups.

Cost isn't necessarily an issue, because with the time we're spending, I'm sure it could be justified. We came across Netwrix, but their sales team really put us off. I can't seem to find too many other decent looking product out there.

Any suggestions?