All joking aside I do think that the noise is a very large issue at CanJam. Especially for newcomers to the industry such as myself, any attempt to try an open-back headphone will not do any one of them justice. I'd actually never heard an open-back headphone at all, and perhaps explicitly due to the noise levels, I fail to see all the praise heaped upon open-backs vs closed-backs.
This is especially important when demoing the pricier units such as the Z1R and the Utopia, as well as the Ethers which I had been wanting to demo for so long. They sounded great but differences were hard to discern and it's hard to ignore the outside noise. It becomes discouraging to see the value in these phones in such an environment. Which, sure, is not the ideal place but for many of us it's the only place.
It's fine for the closed-back ones and IEMs (love my new Campfire Vega even more and more with each day, just continues to amaze me), but the other ones will suffer.
It may be costly, but perhaps each vendor can have cheap cubicle-type booths to help with the noise, or maybe instead rent out the large area for the closed-back phones and IEMs only, then have all the open back stuff in separate rooms. May cost more but may end up in more sales.
EDIT: That being said, I would be 100% in for another CanJam in NYC next year! I also now know to use my same source for each headphone that I want to try, and use just one headphone for each source I want to try, otherwise it will be impossible for someone like me to know if how great a setup sounds is more because of the headphone or the source. And then I might be able to tell when it's due to specific pairings.