I took this thread to be about the pros and cons of the Cytronex system not my concerns about their customer service. If someone wants to start a thread about that, I shall be happy to contribute. I am pursuing my own complaint via Trading Standards, which seems the appropriate forum.
So to return to the topic. It's true that we had some issues with the set up of the C1 system. Actually, it was installed not by me but by someone with experience of serving as mechanic to professional cycle racing teams which should, perhaps, raise concerns. I think that the exposed position of the sensor does make it vulnerable to being knocked out of allignment in the rough and tumble of everyday cycling.
However, my original post largely avoided focussing on my particular experience because I'm more interested in the way the market is clearly developing. 10 years ago, the advent of the bottle battery was revolutionary. It enabled the creation of something resembling a proper bike rather than a post war moped. The original Cytronex had a limited range (the battery was 4 Ahr) but it felt like a real bike. It certainly cried out for a Li battery and that eventually arrived with the C1, albeit later than we had expected.
Meanwhile in 2015, a German start-up company had crowd funded and launched a really revolutionary bike in which the battery was hidden in the down tube. The Freygeist weighed only 12 kg and had a claimed range of 100km. It looked a really interesting bike and got rave reviews, but the company went into liquidation in January 2017.
However, the big bike companies were clearly watching and had started work on their own hidden electrical systems. The result is today's offerings by Pinarello, Bianchi, Focus, Willier, Orbea and, in a City bike format, Coboc (there maybe others I have missed). These all use Li batteries hidden in the down tube, usually about 7Ahr, but sometimes bigger. In the case of Pinarello and Focus, power is delivered via a bottom bracket motor/gear. The other examples use rear wheel motors. Ranges of up to 100km+ are claimed, but I guess we will have to wait for some real life reviews to know the truth.
My point is that these bikes really do look like standard bikes. They can weigh as little as 11kg. They don't have a cats cradle of external wiring with precise requirements for bends of a given radius and sensitive cable routing. They come ready to ride and are covered by international warrantees (sometimes lifetime for the frame components).
What about the cost? These bikes tend to come from top end manufacturers and they are not cheap. But what is the cost premiim for the "electrification"? I looked at this for the recently launched Orbea Gain Carbon bikes. These are endurance geometry bikes and can be compared to the non-electric Avant range. Looking at bikes with comparable specs in the two ranges suggests that you are paying about £1200 for the electric components. This is more than the cost of a C1 kit (£995), but not by that much. I suspect that competition between the 5 big manufacturers will also push prices down. Indeed, if you go searching for a 2018 model, you can find a very nicely specced Orbea out there for £1500, all in.
I think this is the way the market is going. The bottle battery was a great innovation but, in the fullness of time, I suspect it will be remembered in much the same way as we think of the innovations of Alex Moulton - brilliant in their day, but overtaken by subsequent developments.