I always go for the noise cancelling with the best passive protection.
The worst case scenario is loss of noise cancelling at a vital moment.
Sennhausers have good passive properties, but their noise cancelling tends to block lower frequencies which may be insufficient for a turboprop- they are well made and confortable.
Lightspeed noise cancelling is very good, and they have good passive protection, but are a little less robust.
Bose passive protection is less, but they are comfortable, with excellent active noise cancelling.