I have auditioned Arcam's and never found them have a particular sound on their own. At that level of gear, it is all about the room, speakers and most importantly the recording quality of the contents. That's my subjective observations.
On the objective side, just look at speaker's measurements, even anechoic ones let alone the in-room measurements, you will see how the basic measurements such as FR, impedance/phase, THD etc., would fluctuate so much that it wouldn't sound logical for we ordinary humans to be able to hear the relatively minute differences between the likes of Arcam's, D+M and Y's mid range and higher models. There are just too many things that can, and will mask the differences between such amps/avrs.
At the end of the day, if the OP believes his Arcam AVR sounded better than they sounded better to him, in whatever ways. Can't argue with one's subjective experience. I have read posts where people switched from Arcam or Anthem's to Denon, Marantz or Yamaha's and were happy with the results, can't argue with that either.
Again, on the objective side, one can't argue which one measured better if the gear were measured by the same person using the same Audio precision instrument and using the same protocols. And that's especially the case when the reviewers are EEs. That's why I would highly recommend people pay more attention to bench measurements done on Audioholics.com and ASR and use subjective measurements as a secondary criteria, perhaps as tie breakers.