I am about to embark on a trip to southern Africa. Flying via LHR to JNB on BA and then continuing on a Comair-operated BA flight. Same ticket. According to http://www.britishairways.com/en-us/information/baggage-essentials/hand-baggage-allowances I will be able to take everything I need for the trip in a rollaboard and backpack on the BA-operated flights. But the cabin baggage rules are significantly more restrictive for Comair according to that page. In particular, the 7kg max weight is pretty much a non-starter with a rollaboard. Anyone have any experience with how strictly Comair enforces these limits?