I think the part that would concern a lot of operators, especially Bush Operators is the level of Electronics that is seems to employ to control it, I know a few Engineers that would bring up this point straight away. The more complex you make something the more there is that can break down and the more parts you need to keep instock to keep it flying or get it back in the air! One of the reasons so many people think of Diesel Engines as being a great introduction to their Aircraft would be because of their reputation as being reliable engines elsewhere, but I know from a few Diesel Mechanics that this is because of their simplicity.
Would the savings in fuel that it produces outweigh the extra costs of maintaining the more sophisticated electronics it employs?
I always felt simplicity was why so many of the engines used over the last 50 years are still the ones we use today.