Is this informal or just a well-reduced sentence?

[Enigma]

This is not a complete waste of time, just not the best use of our time.

1) Would you say this sentence is reserved for informal writing?

To me, it is reduced from the following:

This is not a complete waste of time, (but) this is just not the best use of time.

Perhaps the conjunction was never there, and, instead, it was two separate sentences. But to me, 'just' shows the words after the comma express a contrast.

2) What do you think?

[Audiendus]

This is not a complete waste of time, just not the best use of our time.

1) Would you say this sentence is reserved for informal writing?

Yes. It is grammatical, but rather awkward because of the repetition of "not" and "time". If it had, for example, read "...just a slight irrelevance", I think it would be OK for formal writing.

To me, it is reduced from the following:

This is not a complete waste of time, (but) this is just not the best use of time.

Yes, there is a contrast. But the correct form of the above sentence is "...but just not the best...", not "...but this is just not the best...".

[saparris]

This is not a complete waste of time, just not the best use of our time.

If you had a defined subject other than "this," and if you didn't repeat the word "time," I could see it as an acceptable sentence in written English.

Daily strategy meeting are not a complete waste of time, just not the best use of it.

[Enigma]

Thanks guys. I agree the repeated words make it clumsy.

Yes, there is a contrast. But the correct form of the above sentence is "...but just not the best...", not "...but this is just not the best...".

Interesting that you say this. Why do you think it is a reduction of your sentence and not mine, Audiendus?

And what would you say 'just' is synonymous with here (what's its meaning)?

[Audiendus]

Yes, there is a contrast. But the correct form of the above sentence is "...but just not the best...", not "...but this is just not the best...".

Interesting that you say this. Why do you think it is a reduction of your sentence and not mine, Audiendus?

Because the contrast is between "a complete waste of time" (seriously bad) and "not the best use of our time" (less bad). If you include the second "this is", you have two main clauses connected with "but", which is wrong because the two clauses as a whole are not in conflict. To say that something is just not the best use of our time (i.e. that it is no worse than that) confirms that it is not a complete waste of time (i.e. that it is not that bad). So the two clauses support each other, and thus should be linked with a semicolon or dash, not with 'but'.

So you can include either the 'but' or the second "this is", but not both.

And what would you say 'just' is synonymous with here (what's its meaning)?

I would say it is synonymous with 'only' or 'merely'.

[Enigma]

Yes, there is a contrast. But the correct form of the above sentence is "...but just not the best...", not "...but this is just not the best...".

Interesting that you say this. Why do you think it is a reduction of your sentence and not mine, Audiendus?

Because the contrast is between "a complete waste of time" (seriously bad) and "not the best use of our time" (less bad). If you include the second "this is", you have two main clauses connected with "but", which is wrong because the two clauses as a whole are not in conflict. To say that something is just not the best use of our time (i.e. that it is no worse than that) confirms that it is not a complete waste of time (i.e. that it is not that bad). So the two clauses support each other, and thus should be linked with a semicolon or dash, not with 'but'.

So you can include either the 'but' or the second "this is", but not both.

And what would you say 'just' is synonymous with here (what's its meaning)?

I would say it is synonymous with 'only' or 'merely'.

Agree, and...agree!