That was quick, but not surprising at that price! Should it come up on sale again .....
Pioneer doesn't refer to it as a "980W" receiver, just Best Buy and some other vendors. The actual specs are
140W X 7 (1KHz, 1% THD @ 6 ohm)
80W X 7 (20Hz-20KHz, .08% THD @ 8 ohm)
So I guess it could be called a "560W" receiver, which is still excellent for the price.
The "Guaranteed Speaker Impedance" is 6 ohm to 16 ohm, so if you have 4 ohm nominal speakers you may need a beefier receiver capable of driving 4 ohm loads and if you do plan to try it with 4 ohm speakers you might want see if an impedance chart is available to see if your speakers actually dip below 4 ohms at any frequency.
At this price range, there are no pre-outs except for a subwoofer (as would be expected), but if you are only going to run 5.1 and your front speakers are bi-wired, the Surround Back channels can be configured to bi-amp the front speakers which might lighten the load on the front channel amplifiers a bit.
Steve