$40 more than the recent Onyx 7 deal https://www.ozbargain.com.au/node/814601 but this is the new version of the speaker.
get $30 off $100 at TGG if you are a targeted member and received a code via text (if targeted you should have got it by now) to bring it down to $239 C&C. https://www.ozbargain.com.au/node/822701
price is currently $360 to $400 at other stores.
if you can get around the unusual shape, spec/driver wise it's similar to a JBL Boombox 2 but with a tiny battery. (instead of two 4 inch drivers + two large passive radiators, Onyx 7/8 has single 4.7 inch driver and 2 large oval shape passive radiators - ones on the back)
differences between old and new are:
Onyx 8 power supply is built in, only need to carry the AC cable. Onyx 7 came with a laptop brick.
Onyx 8 has built in microphones for not only hands-free calls but the speaker can also measure itself and adapt it's sound to the room. Onyx 7 has zero mics.
Onyx 8 has bluetooth 5.2 while Onyx 7 has bluetooth 4.2.
they both have a single 4.7 inch (12cm) woofer and two tweeters.
the speaker works while plugged in to charge/power.
they both also have a measly single 3.7v cell as an internal battery. don't expect much battery life outdoors at max volume, some say they got under an hour. if you play indoors at 50% volume you will likely get close to the claimed battery life of 6 to 8 hours (claimed battery life is close to speakers 1/3 it's size).
after watching a review to learn the differences between 7 and 8. seems like using a single small battery was intentional, as the reviewer claimed Harman does this to protect their JBL bluetooth speaker line up.
I also learned there is an outdoor mode (bass cut) for this speaker, it's just hidden in the user manual. for Onyx 8, hold both volume + and - for 10 seconds and it should switch between modes. for Onyx 7 hold bluetooth for 2 seconds, then while still pressing down on bluetooth hold down volume - for 8 seconds to switch between modes.
the default tuning of the speaker is deep and punchy in bass. if you prefer a less obnoxious sound outdoor mode will do this as well as probably help slightly increase the battery life.
+1 for fantastic description, analysis and comparison.