I'll miss the T7 CCR and the nice premium BA check in area, but not much else (and that part of the experience already deteriorated when they changed the fast track security from an entirely separate lane to the far left of the terminal going into the CCR entrance to just a lane alongside the regular ones).

For what it's worth, the disembarkation disasters used to be even worse when CX were using T7, on one BA flight in particular, it happened quite regularly that you'd indeed be stuck onboard for a very long time because the other BA flight arriving before and the CX one already meant queues that went beyond the stairs/slide areas of immigration. Nowaday, it only happens when there is the "wrong" combination of early and late arrivals...