I'm not completely happy with the construction
There is slightly too much spacing and the arrow heads are too big - making the line spacing a bit too much.
Does anyone have an alternative that they prefer?
You could try the variant MnSymbol provides, which is smaller, but may have unwanted consequences elsewhere.
With the fonts that I'm using I find that
It's quite annoying that there aren't any true solutions to this. For those curious, the possible size options are as follows: