Mixed experience overall. One staff member stood out for being professional and courteous whilst three others were rude, incompetent and slow.
Get their early and be prepared to have all your documents ready and possibly more if you get a staff member who feels like making a point about their level of authority.
I would give it a one overall - it really took three people plus numerous calls to their help centre to figure out how to get me a simple document which I could have told them reading their own guidelines - but one staff member was too nice to completely fail them!