Brazilian living in NL, experienced in both. I think biggest difference is Tikkie doesn't give you an easy identifier. Great for privacy, but being able to send money to your email/phone number makes a difference for some real time use cases. QR code helps, but it is not the same.
IBAN works pretty ok as an identifier when you need that. Bank transfers between Dutch banks are almost instant anyway
It is instant provided your financial institution works within the SEPA Instant transfer system
Since last year, all EU banks have to support SEPA Instant Transfer, both receiving & sending, at the same price as a usual transfer (Instant Payments Regulation 2024/886)
If only https://en.wikipedia.org/wiki/EPC_QR_code supported a sepa instant bit so that one could just show a qr code, scan it with whatever payer banking app and authorize the sepa instant payment.
This is what Ideal/Wero does. Because this is the standard for webshops in the Netherlands (and rapidly expanding to the whole EU) the only gap left to fill was that of consumer-to-consumer transfers with just a QR code to scan. Tikkie I mentioned above solves that well enough in the Netherlands, although that bank-run app is horribly laden with stupid ads and deals you can't seem to turn off.