For 2 channel performance, the Arcam.
There is one more posibility to consider though. At the price of the Arcam you could keep the Yamaha and use it for center & surround duty only and get an audiophile 2 channel integrated amp with a HOME THEATER BYPASS feature to power the L/R mains for your two channel listening. There are many much more powerful integrateds that will out perform the Arcam AVR at way under the cost of the Arcam - Marantz PM11S3 or PM15S2, McIntosh MA6300, Creek Destiny II, are some to come to mind with direct power amp inputs or Home Theater Bypass.
If I liked the Yamaha for my HT duties but wanted to improve my 2 channel listening, this the way I would go. Good luck in whatever route you go.
There is one more posibility to consider though. At the price of the Arcam you could keep the Yamaha and use it for center & surround duty only and get an audiophile 2 channel integrated amp with a HOME THEATER BYPASS feature to power the L/R mains for your two channel listening. There are many much more powerful integrateds that will out perform the Arcam AVR at way under the cost of the Arcam - Marantz PM11S3 or PM15S2, McIntosh MA6300, Creek Destiny II, are some to come to mind with direct power amp inputs or Home Theater Bypass.
If I liked the Yamaha for my HT duties but wanted to improve my 2 channel listening, this the way I would go. Good luck in whatever route you go.