Running a Seasonic platinum 660w personally and solid as rock. But from what I understand they are built very solid.
If it could handle 2x290 in crossfire then the Vega VII is a doddle
I'm sure I had that same PSU in the past and it couldn't run my Titan Z at the time lol also what I hate about the seasonics is the poor thin cables
my best PSU to this date has been the EVGA 750 G2