Your showing your age there Ratters : )
RE: 'Don't forget that it's perfectly Ok to have radial circuits today'
Bs7671 which is the wiring regulations Bible for Sparks, was talking about outlawing Ring mains a few years back. Not because they are unsafe, but because Laymen where adapting good circuits without the correct knowledge of what to do (Thus making it unsafe)
Eg, interconnections and split ringmains on 32a protection devices.
Radial circuits are very straight forward and can be branched due to the fact that a 2.5mm cable can carry more amperage (27A without further calculations for volt drop, grouping and thermal insulation) than the 20A protection device. But if a ring main has been incorrectly adapted and split, then the two legs (now two radial circuits) can only carry 27A max but are on a 32A protection device.
Personally, I think they should rule out DIYers from working on thier own systems as the Government has outlawed unregistered people working on Gas systems.
Then the Ring main wil be in existance for a long time to come as it is cost effective when it comes to cable and installation.