Here's an outline of the key differences: Onkyo TX-RZ710 over the Pioneer Elite SC-87 features. The TX-RZ710 has 7.2 channels amplifier and the Elite SC-87 9.2 channels. Both receivers have support for Dolby Atmos multichannel audio format. DTS:X is supported only by the TX-RZ710. We have evaluated both AV receivers, TX-RZ710 has an overall score of 7.5 out of 10 vs 8.2 out of 10 for Elite SC-87.
The Pioneer Elite SC-87 is better receiver in this comparison - check Pioneer Elite SC-87 price.