Mine are very fast, maybe 1 second on the R1. My only issue is the first word of a notification gets cut off occasionally, but it’s rare. Also, custom sounds are a PITA. Network congestion can delay notifications like interference, power issues, repeaters etc.
This may be a necro now but I just ran across it.
One thing you can do is get a cheap radio and plug it into a smart plug. Assign a motion sensor to it so that it comes on whenever there is motion. It has to be a manual one as some are digital soft touch that won’t come on simply from power being switched on. You can’t choose the sound or the song but it is cheap and it works. I’m using an old clock radio here.
Has anybody tried to hack the Harman Kardon Invoke? They sell for $60 now, have cortana built in and have very good sound.