I'm currently doing my PPL and CPL, and i've been using the HMEC250. Its really good and light. The headset don't really clamp down and still allow some noise to get through. Which in my opinion is good as you still can hear some external noises.
And when it fails it reverts back to a PNR. (which i found out after not turning the ANR on)
Its a good headset. Simple, economical, compact and light. 2 AAA batts per side.