The helicopter community is slowly migrating to Bose ANR (except those goofy North Sea guys with an affinity for Peltors).
One company here (and maybe the other two as well) in the North Sea has done tests for nosie reduction in the cockpit and the Bose doesn't come out too well for noise reduction other than at low frequencies when the ANR is turned on. I know of at least one person who has stopped using his Bose and gone back to the Peltor provided by the company! The main problem with the Bose is that it has very poor passive noise reduction qualities for the turbine helicopter, although I suspect that it is very good in the piston world.
With regard to the topic header, I have tried wedges and found them very difficult to set up and noise still seems to get in through the ear pads. I use Serengeti sunglasses and position the arms so that they are just held by the top of the ear pads but do not completely break the seal. It is not ideal and I am still looking for a better way, but it does at least work.
The ear plugs sound interesting, and have tried some with my MP3 player but I would like to try some in the noisy environment of a twin-engined turbine helicopter like the Super Puma.