Why "shorty" Barlows

For what reason(s) would a shorty Barlow be used? Thanks to all for your answers.

Shorty Barlows are very handy for use with star diagonals, when you want to stick the Barlow into the diagonal (if you stick the diagonal into the Barlow, you get roughly 50% more magnification).

There's no other reason to have them, because the standard Barlows are otherwise superior. Shorty Barlows vignette the edges of the image when used with low power eyepieces.
Renato