Does that work reliably in the UK? Germany has similar a similar mandatory service, but the few people I know that switched banks using that service all ran into major trouble, like rent payments, insurance premiums etc not going through and the two banks pointing at each other "we don't know, it's those guys".
In the end, I believe the best course of actions would to simply make account numbers transferable. There's no good reason why I shouldn't be able to switch my bank and keep my account number etc just like I do with my mobile phone number and provider. Of course, Bank Codes being used makes this more difficult (thank you, regulation).
I've switched banks 4 times over the last few years to take advantage of different deals offering a few hundred pounds or so for join-ups. Never had an issue.
Yes, it works reliably and comes with a guarantee that "If anything goes wrong with the switch, as soon as we are told, we will refund any interest (paid or lost) and charges made on either your old or new current accounts as a result of this failure."
In the end, I believe the best course of actions would to simply make account numbers transferable. There's no good reason why I shouldn't be able to switch my bank and keep my account number etc just like I do with my mobile phone number and provider. Of course, Bank Codes being used makes this more difficult (thank you, regulation).