Congrats on your purchase! The full HT pass thru sealed the deal for me. I use the STR preamp for two channel listening and a Marantz pre/pro for HT.
Have been very pleased with ARC. My room is problematic and ARC has helped me make significant improvements in sound quality, especially below 350 Hz. There are a lot of parameters and targets you can experiment with. Some are not documented well, but the main ones are very clear.
Have fun!