We actually already have that. You can follow and threads on our website and I assume all of our Admins watch them over(sections) and get an email when someone post something in there.
The only thing that helps with a SLA ticket system (Service Level Agreement) is not how fast the issue would be solved, but to have a better communication with our people/players. >XI< is not a company or else we have to put up a "Disclaimer" on our Home section of our website.
We all have our lives and issues and our great >XI< we have, but... as far how quick the responses are, a ticket system to me, would not help. It is a good system if you want to automate, to trigger more communication, but we all give time to the fullest effort into >XI</Online gaming the best we can.
Do you really want a website to force people and to punish people if they don't respond in time or have not read the email ? I do not think so.
Personally, I have been online for like 20 hours a day for a couple of years and I am back on track to read it all, to support, but a ticket system, might be a Senior Admin discussion if that happens.