Advice > Anecdote
Your friend’s experience might be useful to know but has to be placed into the wider viva context.
One good story shouldn’t be enough to help you feel better about the viva. Similarly, one person’s negative experience shouldn’t shift you to thinking that your viva will be bad too.
Ask others for help and ask for their stories but consider them alongside the wider advice about the viva, in terms of prep, expectations and approach. One story can be interesting; the patterns and trends in many stories can be valuable.
Anecdotes about the viva are good but good advice is much, much more helpful.