Actually I was hoping to get the Cisco veiw on if this is a good standard practice and are there any security reasons not to allow internal users direct access to the DMZ servers.

well Cisco Tac recommends as much narrowed down access-rules/permissions as possible, not a complete hole in the system....so try to narrow it down to specific hosts and specific services and ports using the access-lists

access-l abc permit tcp any eq 80

access-l abc deny ip any

access-l abc permit ip any any

access-g abc in interface inside

the above should be good