I'm in Christchurch thinking of changing to Spark from Bigpipe.

Mainly looking at changing since Bigpipe traffic all routes through Auckland which adds unnessecary latency when I VPN into home. Plus I generally VPN in via my iPhone which is on Spark, or another Spark fibre connection (so Spark makes more sense than Bigpipe).

With Bigpipe I have a static IP which was just a one-off cost, but Spark change $15 a month which I'm not prepared to pay.

DDNS would be sufficient for my needs to allow the incoming VPN, but I wasn't sure if Spark might have started doing CGNAT on residential connections?