I don't think icing is a big issue if like me you avoid flying through the nastier kinds of frontal weather, and always aim to fly VMC on top when enroute, but that gets you a despatch rate of only about 75% and with something like a TBM one will depart perhaps 99% of the time, and then one encounters a lot more stuff. I know people who despatch 99% in a TB20 and they have some pretty scary stories to tell
