@Joeblow,
as Vietnam were far more superior in terms of teamwork, fitness, passing and movements.
It's not got anything to do with my personal comfort level, Joe. I wasn't trying to avoid your question, nor am I now. But this is more complicated than, "Would you use it in your writing?"
My foremost concern, having been an EFL teacher for almost a quarter century, is to get for students thee most accurate description of language possible.
I think that the word 'superior' is simply a more formal choice of comparative so it sounds more natural, [because it's more common] when it is matched/collocated with 'far' or 'vastly'.
Which of the two, 'far' or 'vastly' do you think is more commonly collocated with 'superior'? [Check at the bottom of post for results. Don't peek until you've made a choice]
There are countless phrases/words/whole sentences even that I use in speech that I would never use in some of my more formal writing; in other writing situations, some of them probably, others it's less likely.
I'm completely comfortable with all the language I use, in whatever register it might be. Of course, like everyone else, at times I self edit, writing something, then choosing another manner of expressing the same thing.
Just as regards memory, it's extremely difficult to say if I have ever used it in my writing up to now. [Notice the redundancy]
I know it's grammatically correct, of that there is no doubt. What is there that could possibly make it ungrammatical?
But I too am more comfortable with vastly/far superior because those are my, how can I phrase this? the collocations most common to my dialect/my neck of the woods.
vastly superior - About 3,210,000 results
far superior - About 16,000,000 results
Should we all be forced to choose 'far', for every register of English, just because it is the one that most people use?
Here are some other results you might find interesting.
far more superior - About 2,870,000 results
vastly more superior - About 14,900 results