Someone once suggested running slow indicated the watch may need a service, but fast within reason was okay. Not sure if this is true or not, but most of the watches I have owned have tended to be fast.
I think the only watch I’ve ever owned that kept perfect time was a 10 year old Steinhart. All the Rolex etc owned have had different levels of running fast. From a second or two, to maybe 5 or 6.
Must admit, don’t wear decent watches when doing any sport or when in bed so I’m sure this has an effect.
Doesn’t bother me really, it is what it is.