1f56bc31_ox_vs_App___SharePoint_Dragons__Farm
[0] Should IT pros worry over it? [Sandbox] Due the the limited CAS permissions and resource throttling system, IT pros don’t have to worry. [Apps] Apps are able to do a lot via the client OM. There are some uncertainties concerning the safety of an App running on a page with other Apps. For now, this seems to be the most worry-able option, but we’ll have to see how this plays out. [Farm] 
Definitely. This type of solutions run on the SharePoint farm itself and therefore can have a profound impact.
SharePoint 2013: What to do? Farm solution vs Sandbox vs App | SharePoint Dragons
Farm