Yup, they have a new compressor for the MW54, it's supposed to increase thrust... I'm currently repairing mine after a bad crash. I bought the new compressor+inlet and hopefully will be able to run it up by next month.

As for life expectancy/maintanence, the only thing that wears down (excluding inadvertant ground encounters) are the bearings. I've heard of people running for 150+ hours with the original bearings. The neat thing about the MW54 is that you do your own maintenance.