Not a recent experience, but we did this flight a few years back, just after the A380 started on the route. We were late leaving LHR and landed after the Chinese flight. It seemed to take an age for each group of passenger to pass customs, plus customs booths started to close down which really didn't help. It was at least 2-hours, then a massive queue at car hire it was gone 11pm before we were on the road. Then to top it all off, Interstate 405 was closed for roadwork with non-existent diversion signs!