I leave my 1120 in sleep mode (not deep sleep) and it comes alive as soon as you select in input (e.g. stored vTuner station) from a remote device (tablet, smartphone, pc). Same if you set Spotify to stream to the Spotify Connect of the 1120. Don't see why a few seconds delay would be annoying, but I guess that's down to personal preference.
I have no issues at all with HDMI ARC (connected to an LG OLED), but it may depend on your TV set. HDMI ARC is supposed to be an industry standard, but manufacturers have some freedom of choice which and to how to implement features. From the 1120's side, I would say the firmware is stable and there are no issues with HDMI.