Once of the nicer features is that they offer an "encrypted password" where you login to quay and click the "generate encrypted password" option in your user preferences. Then instead of hardcoding your plaintext password into your docker config json, it puts the encrypted password that is only applicable to quay.
For those that use LDAP authentication for this, it makes is a much smaller attack vector.
The per-team "organizations" is very nice and allows you to give teams their own flexibility while still running things within your own firewalls (on-prem or in a vpc). It is an alternative to docker hub with a lot of really nice features.
The ability to do scheduled mirroring of images from other registries (such as docker hub) and replication between different instances of quay is also really beneficial.
Disclaimer: commercial quay enterprise user for some time.
I have found it significantly easier to use, myself. Every time I try to use Docker Hub I get very frustrated very quickly and start trying out the competitors again.
For those that use LDAP authentication for this, it makes is a much smaller attack vector.
The per-team "organizations" is very nice and allows you to give teams their own flexibility while still running things within your own firewalls (on-prem or in a vpc). It is an alternative to docker hub with a lot of really nice features.
The ability to do scheduled mirroring of images from other registries (such as docker hub) and replication between different instances of quay is also really beneficial.
Disclaimer: commercial quay enterprise user for some time.