I've just joined this forum because I was curious about other people's opinions on this.
I test rode the prototype yesterday in Bristol and really liked it. Honestly, it rides as well as a non-electric Brompton, folds almost as small, considering it's a prototype that's been hawked around most of the country for months it seems to be durable, I rattled it over some cobbles and it felt tight, the people even seem nice (I've no connection). The slide-in battery is a far better solution than Brompton's bag and obviously during the Kickstarter it's far cheaper.
You can't fit a hub gear like a Brompton because the motor is there obviously, but the motor takes care of starting and hills and the single gear is chosen so you can easily cruise at 25kph even with the motor off. I do wonder if range might be a bit of an issue - I'm a bigger rider so any time it's heaving me away from standstill or up a hill I'm going to be draining juice faster than someone lighter, and 30 miles or so isn't a lot (by my standards).
But then if I'm using it to pop to the shops and into town instead of the car... can't quite decide whether I want one or not.