I think it would be cool to have an option to sort tickets by when they were modified so it would be easier to check what was recently discussed and so on. I knows there's the timeline but it doesn't show comments and replies (and in my opinion it should, it's more of a changelog).
There's a bug in the sorting you just commited, if you have tickets sorted and click a column again to sort them, the sorting variables are appended to the request string, not replaced in it, for example when I clicked a couple of times on the Summary column header I got this "/tickets?sort=summary&order=desc&sort=summary&order=asc&sort=summary&order=desc"
Fixed/Completed.
Field sorting is on it's way, I will add the last updated column though.