Being a good little WP, I trialled NGCI exclusively during my last work trip - the consequence of which meant that I had to use my WP card for pretty much everything, including lounge entry. The bag drop did not work perfectly, but was adequate and at the other end it was relatively effective. Though slower than a simple BP scan at the gate, the card/receipt system worked relatively well (I'll miss them, but I guess you can probably live without a cardboard BP).
At each of the MEL, SYD and BNE lounges, my card was flashed and that was it. I even stopped at the J lounge counter to check if I needed to get a boarding pass or something, and they said the card was sufficient for everything. I was concerned about arrivals access (which I did need to use once), and whether or not I would need to refer back to the rules, but at no point did I need to use anything but my card for entry.
Mind you, on each visit the lounges were packed full of non-ATA visitors (mostly guests I would have thought) and I imagine will soon get more packed with newly-minted double SC'd WPs. Other than the crockery (mentioned elsewhere) the food/service/furnishings were nothing more than average, so I do wonder when the next round of enhancements will strike and what they will look like. After trying the pizza and the new hot food selection (not special at all), I actually miss the NPPPs. I would have hoped that some of the survey feedback regarding the lounges would have translated into genuine improvements - I'm still baffled as to the barista situation, let alone the narrow windows for hot food. And after a few reasonable 'island' dining experiences in SYD, was very disappointed that there was no corresponding service in MEL or BNE, despite the tables being laid in the same way.
So I gave it a red hot go, but for me the trade off for losing ATA was certainly not worth it. All that remains is for Virgin to start delivering on their big talk about their own service improvements for me to start shifting over (and they could take some big hints from Virgin America) - though perhaps QF is rather cleverly banking on the fact that they will not be able to deliver on those either.