IMHO, having (liquid) hydrogen gas tank on any kind of vehicle would be extremely dangerous, because of risk of (leakage/rapture caused) explosions!!!
Even gasoline is also a really bad idea: just ask countless people who burned alive to death!!!
IMHO, safest, & also environmentally friendly, fuel to use, for all kinds of vehicles, is BIODIESEL!!!
(Until batteries become powerful & cheap enough for all kinds of vehicles!!!)

While I do hope the low cost-per-mile claim proves to be true, I highly doubt that it will come to pass. We have been here before - an exciting new technology or service arrives promising great benefits for all with attractive pricing - only to appear at a much higher cost and marginal capabilities/coverage. These startups will have to address the fact they must make a profit to survive and endure. This includes answering to shareholders who demand ever increasing returns on their investments, and the wide variety of air space and safety regulations, and regional taxes in areas of operations. I expect, that for at least the first decade, such "flying taxi" businesses will focus mostly on catering to the wealthy and corporate customers and will remain a luxury few will be able to enjoy until economies of scale start to lower costs and increase availability to the masses.

Those are all good questions Loz. There's no way that this air taxi will have comparable costs to an Uber ride, even if the Skai is full of passengers. Still, talk of cheap sells, and it may get this project off the ground by all the publicity of being one of the first, which will get people talking. The time saved in flight will undoubtedly be compromised by getting all the passengers ready to fly from one location and again when landing at another (and then they have to take an Uber ride to get to where they really intended to go).
It has exciting promise though, albeit a rather noisy one, and the novelty will help it take off, but flying this taxi in a city where it will be in close proximity to people may be too risky for the FAA but who knows? Blade Runner takes place in 2019 so the introduction is timely, sort of. This will be immensely helped if buildings are built with or modified to have heliports on their roof structures.

First: this thing looks awesome, I love seeing new innovative developments in aviation. Huge props and kudos to the team developing this interesting vehicle. Safety is easy to handle with rocket deployed parachutes and the like.
Second: I can see something like this being very useful for emergency response because the small thrust propellers have a smaller swept area than a traditional helicopter rotor.
Third: there's no way to be more fuel efficient than traditional helicopter rotors because they are wings not propellers. And it's just physics. Sure, a gas/electric hybrid is much more efficient than a pure piston powered vehicle, but that setup will still always be more efficient with long rotors over propellers.
Fourth: noise pollution is a serious issue. Propellers are LOUD. Eight propellers is lots of LOUD. I see no mention of this and no physical efforts to tackle this issue.
Fifth: flying costs more than moving things on wheels. It's a fact of physics and isn't going to change. The closest thing in efficiency is lighter than air vehicles. But they are big and slow...ish. So it's still not a competing product. Even if we should be using them far more than we do for air transport.
Sixth: I don't want our skies as crouded as our streets. That will never be a good idea.

Even with all the negative comments there has to be a starting point for this type of flight. No one knows where this will lead to in another 10 years. In this age of technology things move very quickly.

One thing these companies must just wake up to including Volocopter.
People WILL NOT climb into an air taxi without a pilot. It does not matter how many redundant motors/esc/s batteries flight controllers, Compasses, receivers, ballistic chutes you put into it, you will HAVE to put in a pilot, you HAVE to !!!
People just WON'T fly without one even if it's safe. Mainstream air transport have had autonomy for 2 decades, will YOU climb into one without a pilot ??? The answer is NO you Won't !
Now that this is said and done. I praise the technologies behind these machines and especially this one, this machine looks Stellar, the sleek motor mounts and motors and rotors ! ! ! The whole construction the main Pod housing the passengers, the interior, the lights everything ! ! ! and absolutely MUST be brought to life ! ! ! Do NOT fade away into the background please bring it to life ! ! ! Especially now that VOLO has received the full steam go ahead approval to produce commercial Copters and start utilizing it in Dubai, Singapore AND Germany ! ! ! The world is Finally starting to wake up and catch on ! ! !

People WILL get onto an elevator without an operator. There WAS a time when they might not. Driverless vehicles are an obvious extension of the elevator.

The FAA isn't gonna let a bank of 21 year olds remotely fly people around the sky, they aren't gonna waive all of the rules about flying over--let alone LANDING--amidst crowded cities, they aren't gonna solicit--ERM..."work hand in hand"--advice from a glorified drone manufacturer.

He's quite the salesman, Loz. There is no way in Yell his helis can compete with Uber cars costwise. If nothing else, the vehicles are many times more expensive and the pilots earn +just+ a bit more than a taxi driver. Also, given that probably 85% of back yards aren't legal in which to landa and couldn't handle an aircraft (blow all 3 fences down at once), makes me think he's blowing even more smoke up yer skirt, sweetie.
That said, I want to go ride in one tomorrow! But can you imagine the lines to ride one if they're that cheap?

My concern is the noise, our skies are already too noisy in metropolitan areas. The current numbers of news helicopters, and vintage recreational aircraft already are an affront to our right to silence! Some of us still enjoy sitting outside.