Used for 2 weeks in 3 different cities. No issues, was asked for ID, but as soon as I explained it asked for a pin they seemed to be ok with it.
When withdrawing cash, Davivienda seemed to work without any charges – actually used the opportunity to get a few more monzonauts on board when I showed a few relatives (who also live in London) that I saved £20 on a £190 cash withdrawal simply by letting Monzo take care of the exchange rate instead of the ATM!
One caveat is that for one withdrawal the ATM said there were no available funds, yet still took the money from my account. Thankfully it was ~£5, but even after submitting the form for the claims process (after using the in app chat to get advice from Monzo), I still don’t seem to have had an update a few weeks after. This could be because this is a process that takes time though – one bit of feedback is the claims process is very manual (you have to enter a lot of details that Monzo already has), so definitely opportunity to streamline the process 