I think Os Ticket is great!
Actualy i using Hesk Help after Osticket becouse support multilanguage in the default version stable who you can download, email piping and you have more status for ticket like:
Open
On Hold
In Proggress
Waiting customer reply
Wainting staff reply
Closed
Another suggestion should be operator can chose the new ticket status after operator reply so operator can write reply and before send with the send button decide in drop down menu what will be the new status after the operator reply.
It's good to be able to block a ticket and prevent new reply, sometimes!
Also evry client and operator message should be editable. Some times client message should be editable by operator for correct some bad view or remove some information.
You can see some of this future in the Hesk Ticket and develop better version.
Today i have the problem (Hesk) have problem with pipe function and fetiching function to because Hesk delete the email after a ticket is opened and dasn't have the same function here for move the email in other folder. This is better on you.
I hope you can take some my suggestion and delevolp a better version who can i use.
Thank you and sorry for my little english ^_^