I’ve used arcam products for awhile and the av40 is a nice upgrade over that Rotel 1576ii. From 13ch to 16ch, arcam has xlr, arcam has dlbc with 4 subs, arcam has a nice onscreen display.
Nice that they’d do that swap, arcam is a lot more expensive. Also I’d try for the av41 that has new hdmi 2.1 for a better overall experience. I love my avr20 and I also like my denon 4700 in another room. Just really is no comparison though in sound quality and performance. Dirac is probably a big reason but that won’t be available on denon or marantz for 6 months.
you’ll love the arcam