Regularly travel from ABZ>LHR then long haul often with minimum connection times. I can get between T5A and T5C rather quicker than checked in baggage. Twice in last eighteen months checked baggage didn't make connection at LHR, but arrived following day. To avoid this problem took just hand baggage on a 10 day trip to South Africa. Worked fine but for the SAA sector (JNB>LVI) where SAA have a smaller than BA hand baggage size and a 8kg weight restriction which they enforce by weighing your baggage before check in. So had to check in the hand baggage which didn't arrive till following day. That's real life - the smart traveller looks up the restrictions takes hand baggage which fits the gauges and gets on first (Silver helps) so they can put the baggage in the locker at the front before they fill up.