Of course it is anecdote: I didn't personally experience it - as is your account just anecdote to me. You do a LOT of work with graduates across Scotland - so does he. And as I know him in real life and what he does, that is actually a more "reliable" opinion to me.
To add to the anecdotes, a friend advised her son not to go to Edinburgh Uni to study Maths, as she, as an Edinburgh Uni Maths graduate, did not rate it. Of course, her ds didn't listen to his mum (
), went to Edinburgh to study Maths and then realised his mum had been right
. He ended up changing to something else (Chemical engineering?).
Personally, I'm more concerned about the teaching experience and support, since that is what will make the difference to individuals. Comments in The Student Room and been previous posters on this thread who have expressed some concern about Edinburgh (although not sure which subjects; there are no doubt some subjects which are outstanding)
But the more important point is that we have to encourage our children to be happy with their choices. I never said a word to ds "against" Edinburgh, while he was waiting to hear from them, as I knew he had his heart set on going there (but not so much for quality of Uni reasons - more to do with where he wanted to play rugby 
). Now that he's not, it's my job as his mum to ensure that he is happy with his choice and doesn't have regrets.
League tables can be manipulated according to what you measure (and across subjects), so that you will see all sorts of different rankings for all sorts of Unis, from different organisations, depending on whether they are ranking (and how weight they weight them) overall experience, undergraduate teaching, student experience, research, graduate prospects immediately post graduation, graduate prospects within 6 months of graduation ..... soooo many variants! 

And I say that just as an impartial observation: I went to St Andrews and loved it (and it come out very well in some rankings and it's also very good at galvanising social media to good "student experience" scores) but ds hated the feel of the place (for very valid reasons the same reasons I'd loved it-- ), even though he acknowledges it has an excellent course. He also chose not to apply to Glasgow as he felt that Strathclyde was the better of the two courses for his specific interests and he's turning Strathclyde down anyway. At the end of the day, our children will perform best if they go somewhere they will be happy. 