I have the "Basic" Onkyo amp and have had it a few years. It replaced a Denon one that was not keeping up with the times and yes the Denon sounded better but the Onkyo is still very good and better than my mates Yamaha system and far better than the grouped systems from Sony and the like.
I use some 15 year old Kef Cresta 5 Floor standers, and a mix match of other speakers with only okayish cables – so that part of the system is much weaker anyway and needs money spent on it.
I was watching Mamma Mia on Bluray through the PS3 connected via HDMI to the Onkyo last night and it was okay – but for some reason Pierce Brosnen sounded like a stangled cat 😆