Improved ACL editor for Windows file permissions
Take a look at SetACL Studio. It was designed to be a replacement for Windows ACL Editor. It has an intuitive UI (resizeable, of course!) and is much more powerful than the original. It even has undo.
[I am the author of SetACL Studio]
If you're doing large-scale changing of permissions, I'd suggest automating it with icacls.exe or the get-acl and set-acl PowerShell cmdlets.