Below a list of what I absolutely find mandatory for a ticket system and not available on osTicket:
- Ticket Linking or merging
- Ticket Status customization
- Tracking time tool
What can be improved:
- Data export - Statistics (not enough in current osTicket)
- osTicket Customization improvement
And what is not mandatory to live but can be a pleasure to have:
- Chatter functionality
I released a mod for 1.6 with ticket linking and categorization. I swear I will eventually find some time and port it as a plugin now that the eco system in here.