We switched this on a year or so ago, as the children started to be more independent with their use of devices, the Mac and so on. I did some checking on it of very obvious searches to make sure things were being blocked - naked lady, Matt Smith in the shower (!) and so on and all these things were correctly blocked on all devices linked to our BT Hub.
I had reason to check it again recently, not really sure why, just an instinct thing and discovered that despite the fact it was turned on, nothing at all was being blocked any more. So I deactivated and reactivated, only to discover that very little is now blocked in the way it was before.
The odd thing gets caught (typically, the things that you don't mind going through, so I override to approve certain websites) but the dodgy photos and everything get past BT so called Parental Controls.
As a result, I have put on Google Safe Search which hopefully achieves the same end, and have restrictions now set on each device, but I am seriously miffed that BT appear to have moved the goalposts.
I cannot bring myself to have yet another 45 minute phone conversation with someone very helpful, but who doesn't actually understand what I am getting at and who simply puts me through to "the technical team" who then switch it all off again, as happened yesterday, so can anyone shed light please, or has experienced the same?