One thing that is different on the Onkyo TX-SR304 that is not as common on other receiver brands, is the different color coding used for the speaker connections. The left and right front speaker connections are the traditional red and white, but different colors are used for the other channels. This definitely makes it easier to associate each connection with its proper speakers.
Also note that the speaker terminals are push connectors, rather than the more heavy-duty screw-on speaker terminals found on more expensive home theater receivers.