It depends what you mean by delays in diagnosing, @Peridito.
Incubation time seems shorter (SA data) so you’ll get symptoms quicker and hopefully test quicker.
Only 50% of initial PCRs can detect S gene drop out which signals likely omicron (likelihood of it meaning that increases, as omicron spreads).
Those swabs are then sent for sequencing so that takes ?48 hours longer, so in that sense it’s delayed.
Official figures seem to show suspected and confirmed case numbers.
The ‘only 50%’ of samples presumably mean we should be doubling the reported numbers even just to get an idea of UK case numbers among those actually testing.