If you already run PASS/3Sys on-prem, then you are not at an advantage. Cloud Hosted is much the same as On-Prem with remote access (i.e. 3Sys is web based, so can be made visible through your firewall, and PASS could be used via RDS or similar).
If you mean the new Cloud Service 'HUBmis', I don't think it's yet available, its still in development. There are sneak peaks though which give me a warm feeling: https://www.wcbs.co.uk/hubmis-sneak-peek-series
I could be wrong, and would also be interested to know if anyone is using this yet!
