I would agree with Mr Grew on this matter.
I would add even more.
There is:

5. skillful, boring and tidius performers

One can be as skillful and one can possibly be and as intellectual as one can be, but if the audience is not involved they will not listen.

Now days performers are playing for critiques, for people who will open the doors for them to perform in different venues.

What the critique expects and what an average member of the audience wants and expects are two different things.

The audience wants entertainment and learning experience.
Then there are musicologists. They would expect you to play all embalishments correct,  the interpretation in a style of the period.

But does the audience care about it?
I don't think so.


I never heard anyone leaving the recital saying: his performance of trills and other embelishments were good. All they know is they either like it or they don't.

This morning performance of Alexei Lubimov was both intellectual and stylish, and not boring. (I even want to say there were emotions there too. He did not play like a machine who knows where the keys are. Some pianists as expressive as robot playing a keyboard).

In Associated Board books they have put in good embellishment suggestions. It is very useful because not every teacher has access to the library and time to inverstigate in depth. I always like to see what they suggest and make my students play that way.
I like their notation of embalishments too. 
I read a book (don't remember the name) where Bach's system of embellishing was described, but still am not certain or may be did not understand how to do it in each case.

I am getting better with embellishments, but it is far from being good. I am playing a few pieces from English suite in A in Russian old edition. It is not bad, but I should see Urtext. I have a few students that are beginning to be interested in Bach, Scarlatti, etc.