For those interested... I used VA Wifi from CHC - BNE for the 2nd time today (used it a few months ago on BNE-CHC).
Unlike the first flight, coverage wasn't available on the ground so it didn't start working until just after take off.
Plans were the same $6.99 for 1 hour and $12.99 for the full 3h 40 minute flight.
Speedtest.net kept timing out on the upload tests however the pings were around 500-700ms (standard for satellite) and downloads were around 0.4-0.5mbps.
I also did 3 tests (at different times of the flight) on fast.com and got 340kbps, 400kbps and 350kbps.
YouTube 144p live streams (like ABC News Live) didn't work (way too much buffering) however 144p standard videos worked fine. Surprisingly I was able to watch Channel 7 live with no buffering (albeit low quality) via their 7plus website. Throughout the entire flight, I was able to download around 300mb of data (video streaming, browsing etc) which isn't that bad especially given the pathetic speed tests.
This time I was able to also get some screenshots of the coverage map which shows that all VA Trans Tasman, Bali, Port Vila, Port Moresby, Honiara and Nadi are 100% within the coverage area.
It's hard to tell but I'd say that Samoa, Tonga, and Rarotonga flights might just be out of the coverage area (but that's just based on my view of the route map and wifi coverage map below)
VA Route Map
VA Wifi Coverage