I used my BOSE on the Tiger for a year with no problems. I have recently got the moulded earplugs and will wear them under the bose. The logic being the bose is comfortable and makes flying for a long time comfortable, and the plugs protect high level hearing.
I have tried a helmet, albeit on a SAR S61 and I hate it with a passion. Each person has their own opinion, and if they are still doing it I suggest you do the BOSE trial, try it and keep it if you like it or return for a full refund.
Good luck whichever way you go.
Si