Two sponsors living at the same address can face completely different rulebooks depending on nationality and free-movement history. Non-EU partners often discover late that the EU-law route and the Dutch national route diverge on exams, income testing, and even where the application gets filed.
Quite different, and it depends which kind of EU citizen. If your partner is a non-Dutch EU/EEA or Swiss citizen actually living and working (or studying, or otherwise self-sufficient) in the Netherlands, you apply under EU free-movement law rather than Dutch national law — filed from within NL rather than via an MVV from abroad for most nationalities, no basisexamen inburgering buitenland, and a softer "sufficient means" test instead of IND's stricter income-and-sustainability regime. It's not literally income-free, just a different and generally easier bar. A Dutch citizen, by contrast, defaults to the stricter national route unless they've genuinely exercised free-movement rights themselves — actually lived and worked, not just visited, in another EU/EEA country for a meaningful period. Case law (Surinder Singh, and the Dutch-specific O. & B. ruling, which points to roughly three months of genuine residence as a rough floor) lets that person invoke EU law on return with their partner — informally the "Europe route." Without that history, a Dutch sponsor is stuck with the national route's income and exam requirements like anyone else.