Needing Some Feedback

So as I expected, working with shelter dogs to set up a flash and having a dog stay in a good position relative to the flash is a challenge. In the time it takes to get one or two good shots using the flash, I can bang off a number of dogs without the flash and using a fast lens.

 

What do you think? Is it worth the effort with flash as compared to not using flash?

 

Good, honest feedback much appreciated!!

Done