Then there's convinience. People will be free to transfer money across the continent, and also to friends and family without any costs (some countries have that, some dont).

I'm not sure about that part. If GNU Taler is to serve as the digital euro, that has been designed to be taxable. for this reason when transferring money to a friend instead of a business, that will have to go through a third party that sees the transacting parties and the amount.

Taler is very promising, but with it (or another digital euro implementation) we will still need easy access to regular cash.

Surveilence

A regular transfer takes at least some hours/days. With digital currency the transfer is instant.

Apart from that, surveillance. There's a (de)centralized register that shows how much money there is ti be found on any account at any given time.

The existing Euro does not have a proper system for day to day transactions. Transfers are currently handled by SEPA, which are only suitable for things like bills. This means that a lot of people especially in less developed EU nations end up using an international bank card, i.e. MasterCard/Visa for day to day transactions.

Details are somewhat vague, but the ECB's website seems to have many good assurances. This even includes strong privacy features, such as offline capabilities and cash-like privacy.

FAQs on a digital euro - https://www.ecb.europa.eu/euro/digital_euro/faqs/html/ecb.faq_digital_euro.en.html#q1

The digital euro will be centralized on the European Central Bank, so the transactions do not depend on some local banks. It's in direct competition with the banks themselves. But yeah, not that big a difference for the end user imho

Late response, but anyways: the big advantage over regular bank transfers is you can use it like a virtual card without Visa or Mastercard. In essence, the biggest draw is pushing US companies out of the EU financial system.