Hi,
In most of the projects I'm managing (in the "old" version of jira) we are frequently using the Time estimation and time tracking fields on stories and tasks, and those fields are not available at all in next-gen, so far as I have been able to see. Is this something you are going to add, is it already there but renamed and hidden somewhere, or has it been removed completely as a feature, and in that case why?
It is an extremely useful tool to generate reports of time consumption and time management, so I don't see why it shouldn't be a part of next-gen as well.
Regards,
Marcus