Whilst I appreciate the whole theory and design of the rotary engine, they certainly aren't for everyone, they are inefficient, produce masses of heat (which was great for us with the oil coolers and big rad) and probably drink more petrol than the cossie we're putting in. I think the main downfall of them is more operator errors than anything else, they drink oil and Average Joe forgets to check it every so often which ruins them. From what I get of it most issues are caused by either low oil or bad coils causing a misfire and whatever the rotary equivalent of bore washing is called.
The mps engine would have been an excellent choice for them from the factory, but chances are they would cost 5 times as much secondhand, and we would never have got the opportunity to create this particular monster