Considering that you have access to the Case object within the Sales Cloud what are the limitations if any?
Cases are the same in both Service and Sales cloud, the benefit of Service Cloud are for High volume and SLA based support environments, with the specific addition of the following features:
- Service Cloud Console
Open CTI, Service Cloud portals, Knowledge and Live agent are all available with either Service or Sales cloud licenses and with the exception of Open CTI all require per user based licensing.
Mohith mentions "field service management" as being included with Service Cloud. This is a bit squishy. I wouldn't say that there is anything that is inherently Field Service-y about service cloud. It has cases, not necessarily something like Work Orders or a Dispatch Schedule.
full disclosure: I work for ServiceMax, a force.com native field service application.
With little bit of my Business Analyst skills i could say that service cloud offers agent console, service contracts, entitlements, field service management and SLA.
I think these features we may not get with sales cloud Case Object .Assignment rules,escalations ,workflows all these should be still available.
This is as per my knowledge and this is more suited to business at salesforce. I hold no responsibility in stating above .
Update after remark from Peterson:
knowledge ,Live Agent ,Portal require featured license as i found scanning through documents.