ATR 42-300 are not unreliable, but the new model are better, because they are more powerful and more confortable.
If some airlines are buying, renting, leasing ATR42-300 is because the new models are really hard to find.
The 42 is perfect for short runways and even unprepared, The plane has great performances.
About the ice......well maybe is not the best, if the boots are not refitted then just avoid icing conditions.
In fact the ATR42-300 burn less fuel and is not much slower.
I read today that 2 ATRīs are heading to Libya,