How did you find the Bose X? I am thinking about treating myself to one when I get my PPL... a little bit of incentive to make sure I get it done!
I have tried the Bose on at the aviation expo they had at NZAR a few months ago... was very comfy... and the difference it made when you flicked the switch (a gentle 'woosh' and then silence) was unbelievable... However, I have not been able to try one with just a firewall between me and a noisy 4 cylinder at 2300RPM

I also heard that the Bose is better than the DC X-11 passively... but I have not tried the X-11
"Son, we are about the break the surly bonds of gravity, and punch the face of God." -- Homer Simpson
