Hi,
I am an engineer and have seen them installed they are very clever and do the job well.
But, This is not intended to sound negative, there has to be a word of warning, frequently I see posts about electricity usage and how things have gone up, and where's all this electricity been used.
Well before you get too giddy look at the running costs, its not free, the one I looked at is 1.8kw per day, not much but it needs to run all day and every day, if it is in use that's 657kw per year, forever, as one of earlier post suggest you need to look at annual maintenance servicing.
If you have issues with land and cant make a traditional fosse work they are a great option, but as a traditional Yorkshire man with long pockets and short arms look at all the options first, a bit more sand up front might cost more, but it free to run it.