Just to add to JT2's comment, I have flown a number of EC135s with TM power over a few years in the UK.
There were starting problems with the early versions, if you did not let the prime pumps have a few seconds to do their thing. There were also early problems with the HMUs. However, apart from that and certainly with the later machines my experience on starting is exactly the same as JT2. Perhaps the reputation for poor starts came from that early experience?