SX10N is the first endpoint that is supported to register to Cisco Spark cloud service. Starting from CE8.2, all the remaining SX, MX and DX endpoints are supported to register to Cisco Spark cloud. There are some considerations that you need to take if you want to register the endpoints to the Spark cloud. According to the release notes:
So it means that SX10 and SX20 are supported only when using TRC6 remote, but not Touch 10. On SX80 only directing pairing of Touch 10 is supported, but not network pairing. This is something that people will possibly miss out if not reading the release notes carefully.