I'm frustrated with the way in which Spark and also a large portion of other Telcos do their roaming. The fact that pretty much every data connection on "4G Roaming" is VPN back to home base in NZ. This introduces serious reliability issues which I've noticed the last 3 times I've been in the USA including right now, over the past 6 months here on and off.

The connection ends up consistently being "worse than satellite" in my opinion. Connecting to a New York server from California introduces nearly 1 second of latency. When trying to load a page for something from a US based server as you would reasonably expect to do while in the US can take anywhere from 30 seconds to a minute depending on how many objects the site has from various different locations and how many threads the browser does. 

It's completely atrocious and I'm surprised I haven't found that many complaints about it. There are benefits of course being routed back to NZ under your home provider, mobile portals work for Spark for example without authentication under the old way of doing things. This no longer is applicable anymore however because your forced to login to my spark whether you come from the account device or not so this is no longer of any benefit.

Mobile calls use the roaming carrier to make calls I just wish that roaming data would do the same. It's a sub class level of service that you are expected to pay a premium for (I tend to do 1GB for $50)

Lastly I would add that the service is often unreliable and cannot be depended on, google maps takes forever to load along with Uber and sometimes your not sure if the data is actually working so have to flight mode in and out.

I'm going to upload a few images below showing some trace routes to an NYC located server just to show path:

This is an example of ping time to the NYC server which is "Worse than Satellite" 

Worth mentioning is the appalling latency just back to NZ based servers as well is around 650ms round trip.

I'll sign off with one final note - AT&T native SIM is around 220ms to NZ and of course around 40ms to New York, yahoo loaded in 5 seconds using developer mode on the browser monitoring network resources and 1 minute 45 on Spark Roaming on AT&T.

Time is of the essence when travelling, needing to book taxis, find directions - it's a complete nightmare under the current spark service offering and this is 3 recent US trips worth of reporting going into this post.