Hi. Are you sure that the Yamaha is the RX-V661? If so, that's a pretty old model and won't have the ability to decode the latest lossless audio codecs (i.e. DTS-HD MA and Dolby TrueHD). The Marantz is a newer model.
Is this for a surround sound system? Do you want to be able to decode those audio tracks?
If it were me, and it was for a surround sound system, and I had to pick between those two, then I'd go with the Marantz over that Yamaha without hesitation.