I don't like the idea of putting a value into a cell in order to get a
formula to calculate something and then to read it back with VBA. I would
not have confidence that the calculation would be done immediately (i.e. in
time for the statement that reads it). Indeed, the worksheet's calculation
might be set to "manual" which would likely cause the calculation not to be
done at all until you hit F9.

To ensure the sheet is up-to-date you would really need to get VBA to order
a sheet recalculation before reading the result cell.

As well as being a bit uncertain, this has got to be a slow way of doing it.
You're relying on the control flow moving from the VBA to Excel and back
again.

As well as this, you've now got an activity that is integral to your VBA,
but is not visible when reading your code - i.e. you also need comments to
explain what Excel is doing.

So, I see "cons". Unfortunately, I can't see any "pros" - apart from the
fact that you're comfortable with it, which is always a big "pro" in itself.