Concerns included that only 35% of the 480 homes would be “affordable”.
Under city council guidelines, half of them should be given that classification.
But the authority said it was happy with a mechanism that means more homes will be built if the site is more profitable than expected.
Bob Colenutt, of Summertown and St Margaret’s Neighbourhood Forum, said: “Affordable housing is desperately needed in Oxford; this is a huge site, it’s capable of generating quite a lot of housing, particularly social rent housing.
“We felt the council wasn’t negotiating strongly enough.”
The plan has already had £10m of government money allocated to it.
TWO has said it will provide up to £100m of “substantial investment into power, utilities and public space” for Oxford North.
Oxford City Council’s planning review committee approved the application on Monday.