I don't find any real problem with Conc in the approach phase. When it first started it was a pain becuase some genius dreamt up "Concorde Standard Approaches" and we had to fit other traffic around it. However, within a few days the crews were opting for "hand jobs" (ie radar vectored approaches like everyone else). In recent years, apart from occasional fuel problems if we're holding, it has behaved much like everyone else and will happily come back to 210kts downwind and 170kts on final.... although most of us like to whack it around faster than that!!
I agree that some recently validated controllers won't have worked Concorde, but neither will many of them have seen 23 in use or certain other less usual procedures. One just has to rely on one's experience to cope.