I have many clients that have upgraded to Sage 100Cloud 2018.  All have been successful and clients are happy.  Reach out to your reseller for assistance with your upgrade.  Sage 100Cloud 2018 has been out for almost a year.  

We are not large enough to upgrade to the Cloud version but have been offered Sage 100c

Sage 100c is the same thing as Sage 100Cloud.  Just a new name.

Sage 100 "Cloud" is a very misleading name, and every conversation I have about it involves clarification that it is not any different than the on-premise solution which used to be called 100c. (Sometimes the clarification results in relief, and sometimes disappointment).

The distinction is branding / marketing, because it sounds trendy and Sage is adding connected services (like the PR tax calculations are done by a cloud service).  The core system architecture is unchanged.

Oh, and we have many customers running Sage 100 v2018 just fine.  We usually wait until the first PU unless there is a specific feature a customer really wants, and PU3 is out so stability is not a problem.

Oh, and we have many customers running Sage 100 v2018 just fine.  We usually wait until the first PU unless there is a specific feature a customer really wants, and PU3 is out so stability is not a problem.