Replacement for Harman AVR645

Hello this is my first post here, so hopefully it will be well structured, i have an AVR645 that i am planning to replace, HDMI switching its not necessary as i output video directly to the TV and as far as listening i would say that i use 80% music and 20% movies, its paired with paradigm SA35 for center and fronts and SA15R for surrounds, a rotel transport and ipod/flac files.
I listen most of the time to music and sometimes use the logic 7 feature.

Among the options i am considering is an Anthem MRX 500 that i can demo with a local dealer (HDMI wanted but not critical) another of my options is going the separates route, with an older arcam AVP700/FMJ AV8 that seems to be cheap used or an anthem AVP and pair it with a rotel/arcam AMP, as far as advice, would you say that ill be able to notice a significant improvement going the separates way?... even if its an older equipment but better quality sonically would it make a great difference? or should i go again the receiver way?... any advise would be greatly appreciated
Another option would be wait until some separates having hdmi 1.3/1.4 go down in price (least desirable path)