Wow, that's an amazing deal for SYD-LHR-SYD on (what looks to be) a world-class F product. Well done - please report back what you think.
As an aside, after recently giving MH J a positive review in this thread, I unfortunately had a pretty poor experience with them last week:
Myself and three friends went to coughet for a "buck's week" last week, and to get us there I burned a little over 125,000 Amex MR points to fly the four of us on MH J for the outbound leg (only Y on the way home unfortunately) - I'd obviously prefer to fly J, and I thought it would be a nice treat for the other three given none of them had flown J before (not even domestically).
Unfortunately, despite being an almost-new A333, it turned out that the entertainment system wasn't working (for the whole business cabin - not sure about the rest of the plane). Never fear, at least there's some "broadcast" looped movies to fall back on - except that all the broadcast loops started halfway through the movies, which is pretty useless on an overnight flight where you also want to get some sleep. To top that off, the headphone socket on one of our four seats was also not working properly, the cabin crew managed to serve the wrong meals to two out of the four of us (and apparently couldn't swap for the correct ones), and a few other minor niggles.
Admittedly none of these are major issues - even all taken all-together - but they were made much more annoying by the fact the cabin crew didn't seem to really give a damn, no compensation was offered (I've heard that normally the airline will give out vouchers or similar when entertainment systems don't work on long-haul flights), etc. I'm not normally a "complainer", but the sum total of all this annoyed me enough that I actually took the time to contact MH (via both their online feedback form, and an e-mail to their Enrich e-mail address) and complain - and over a week later I still haven't heard a peep from them.
As I said above, not the end of the world - but the experience has certainly put a dampener on my previous enthusiasm for MH J...
