SNB, I brought a zulu a few months into my training (2011). I don't have any complaints with them. I concur with other posters that they are noisy with flat batteries. Their true noise cancelling abilities was most noticeable in the Cessna 206 at full noise. I like the blue tooth function for making phone calls, especially checking weather on AWIS.
Perhaps if the ones you were trying were a bit old and unloved the ear gels may have seen better days. I'm still using the original ones on mine, but I've heard other pilots up north change their ear gels every 12 months. If the ear gels aren't sealing properly around sunglasses etc they're going to let in noise that's going to overwork/confuse the ANR processor.
Regarding Bose X our class was split. I did try them. No complaints, just a little bit more expensive. The guys that brought them tended to be the sort that had trouble passing a mirror or reflective window without pausing and staring at themselves whilst wearing their expensive aviator watch/Bose X/mirrored sunglasses etc.......
