I've never worked on the 101's, but from what I hear from the side of our company that does operate them (a couple of BK's and 222's) is that they are much improved from the early models. The Arriel is a great engine until it comes time to overhaul, then it gets very expensive and parts from Turbomeca are hard to come by. With the US military changing engines in the HH-65 and now buying EC-145's, Turbomeca is pushed to the limit in providing parts and modules. We have had problems with sulfidation and power turbine erossion in our 2S1's and I don't know of any that are making it to scheduled changes. We usually run into low power problems well before life limits.