I generally look at high-speed international data plans as a form of insurance. You probably won't need it, and by and large, 256kbps is likely fine for most cases.

But then there are the cases where ... when you need it, you really need it.

I'm pretty good at navigating public transit and such, but I've had my fare share of "stuck in a train station in a foreign country where nobody speaks English fluently and I need to catch my plane" and being able to Google Translate or search for help online beyond what Google Maps offers ... it can be particularly valuable in a pinch, and honestly, it's something where paying an extra $10-15 to solve a problem can be totally worth it in exchange for avoiding a whole ton of stress.