Virtually all of the hubs are designed for German bicycle lighting laws for 3 watts for both front and rear lights, 2.4 watts if for the front only. So, the hubs come in either of those two electrical outputs. (This was mentioned above, I am just explaining why the standardized output.) Thus, all the hubs would be compatible. Some hubs are more reliable, some more efficient than others. And the prices vary a lot.

But, USB ports could be where you find the most differences, as there is no legal standard for them, some have better waterproofing, some more efficient than others, some might not work well with Apple products, some have a cache battery while others don't, some provide a little more wattage than some others, some headlamps have a USB port built in and others are USB charger only.

For charging a smartphone, you want either an external cache battery or a charger with a battery built in so it keeps charging when you stop at a stoplight.

I have the SP PV-8 hub (that model hub does not work with discs), AXA Luxx 70 Plus headlamp with built in USB port (not sold in USA, I ordered it from Europe) but does not have a cache battery.

But you will find a dozen different recommendations.