The User column is always empty for me on the Recipe Systems page (click on number of Possible Systems for a queued recipe). Not yet sure why.
Ok this is because bool(<element_instance) returns the value __len__() which is the _children attribute.
(Pdb) print d_.user and d_.user.email_link or None
(Pdb) print d_.user.email_link
<Element a at 4d78250>
(Pdb) print bool(d_.user.email_link)
Verified with beaker-0.11.3-1.git.187.dac7008.el6.
While a system is using by a user, queue a job on it, user column is not empty now.
Beaker 0.12 has been released.