Maximum Attachment Size

Currently our company record allows a a maxium attachment size of 5MB per attachment, and a total of 25MB per ticket.  We have specific users that have a need to attach pdfs in the 25-30MB range.  Would this size of attachment cause any issues? I was planning to only give particular users this size limit by specificing the limit in their operator records. 

Any thoughts, recommendations or best practices around this?

Thanks.