@ Mtu Black, I am not a doctor but a 'sufferer' for the past 10 years.
My experience is that the cardiologist and the nurses at the clinic only use the manual devises to check. My gynae used manual when monitoring BP when I was expectant.When it is a non BP related ailment and I visit the normal outpatient clinics, I find that they use the digital. However, sometimes when it is very high and, the digital one reads 'error' and starts and restarts without taking a reading severally and you know things are elephant. They then resort to manual reading.
I am but a laywoman and stand to be 'collected' by the doctors on Wazua.
I can do everything through Christ who strengthens me: Phil 4: 13