From what I hear you,ll spend very little on fuel but spend any savings and more on maintenance of the engines.The engines never get anywhere near the TBO and need constant attention.Have a chat with some of the schools who operate them or even better still the engineers who work on them ,they are not impressed.The CAA seem to have a very hands off attitude to the engines,claiming its a "european" issue.I,m sure if it was an American engine groundings would have taken place a long time ago given the shocking reliability record of the engines.All very political or perhaps the CAA just can,t get their heads round the technology!!.