I was upgraded to P+ as part of the trial and so far the only difference I've noticed is VIP on my boarding pass and the (very welcome) Australian call centre. Bit sad that you have to spend $24,000 a year to get help in your own language! It's early days yet so we'll see how we go. I'm very close to P++, with about 3900 SC's currently. I wonder if that would give me 320 kg luggage allowance? I could offset trip costs, running an express freight service.