No probs ..... but just to point out ... it isn't just holding. Unless the mince meat used in the patty is minced from chilled and immediately just before it's formed and then cooked straight away and served than that is where the risk of growth of nasties exists. The reality is that virtually no - or no - restaurant will be mincing freshly during service. At it's simplest you can hang beef to improve it but long "stored" mince at the same temp will possibly kill you. There's a big difference.

In terms of the other trust issues .. it isn't an issue with raw stuff that you can see and sniff like sushi or seafood. If ever you've had a bad oyster .... you then always "sniff" before eating. And with cooked items normally with anything so long as a high bug killing temperature is sustained. Undercooked burger risk is something you will not detect with the nose. It needs to be cooked above pasteurisation point to be safe It is simply a sort of lottery risk that's all I'm suggesting. It's not just my opinion ... it is accepted by most advanced food standard authorities.

As it happens there also isn't imho any taste advantages - only downsides, uless you genuinely like raw mince and raw seasoning - in which case a beef tartare is posibble more appropriate.

Caramelising the outside and internal cooked running juices is where most burger taste lurks apart from all that stuff people add afterwards. It has alway seemed to me it is a sort of misplaced ill-informed snobbery emnating from undercooked well hung steaks - which is normally good where the raw material is prime - where people seem to think it is more sophisticated to eat raw mince in a burger.

Just my misplaced therories ......