I have had a few problems
The silliest one occured a few days ago when "a town called eureka" lost all information on the HD channel about the programmes compared with the SD channel.
I think there have been one or two others where the same has happened. I do not see why they should happen
One instance of F1 running late due to rain so it was switched to BBC 2 at extremely short notice
Otherwise the advantages much outweigh these minor problems.