Nick,
I assume you know that for noticeably less than the price of a new RX-Z9, you could buy a RX-V2600 (or similarly priced, comparable product) with all the latest bells/whistles and add a very good external amplifier with 200 watts/channel across 5 channels. Something to consider. AV receivers are somewhat like computers.....there will always be a new format or connectivity feature at some point in the future (ie, receiver decoding formats, etc. can become obsolete or outdated, whereas an amplifier is a more straightforward and future-proof investment).