The Nexo sounds great....but, the problem with hydrogen fuel cell cars as I understand it, is that a Hydrogen Fuel network needs to be set up (much like petrol stations) which means shipping Hydrogen around the country. Hydrogen is, apparently, a fairly energy-intensive product to make too....and somewhat volatile (but then so are oil products).
The ease of Electric cars is that there is already a network supplying most countries nation-wide with power....yes, charging points need to be installed, but that is much easier than setting up a Hydrogen supply network.
Also, in New Zealand, our electricity is largely clean and green....meaning most power produced is fossil-fuel-free.
I have read some intelligent thinking that Hydrogen might well be the ideal fuel for large trucks to ship goods around countries....but battery-power might prove better for smaller personal vehicles.
The future is an amazing thing to wonder about :-)