I backed the Gemini and it shipped. It's sitting on my desk next to me.
I will note that Planet Computers' communications and updates were just as bad during that campaign as they are now with the Cosmo. Also, the Gemini arrived about 9 months late, if I remember correctly. The Cosmo, going by the progress updates, is coming along faster: it looks likely to be only 6-7 months late. Not surprising, as it's essentially an updated Gemini with extra bits added (new keyboard, upgraded chipset, and the external screen/camera/fingerprint reader).
As for the recent silence ...
At about this stage in the Gemini release, initial assembly and packing had been completed. Then the first batch of a thousand or so Geminis spent a week or so being processed through warehouses before finally making it onto a flight to the UK. Then they spent another week getting cleared by Customs, before being shipped out to customers. It was a rather tense wait because, with nothing to report, Planet "went dark" on the Indiegogo campaign page. (They really need better communications!)
But no, this isn't a long con. If it was, the time for the bust-out passed about 18 months ago when the Gemini was the product.