Do you feel the use of flash,

[USM IS]

Makes this shot any worse than it already is?

 

[EGVphotography]

It depends what kind of flash you used, if you use the built in flash it makes image look like this flat and bad.

 

[ifi]

Now that you've mentioned
I can see the catch-light in the bird's eye, and the wood on the background is a bit shiny. BUT I am not an expert

 

[USM IS]

With a 600mm X 1.4 with 580 EX with a Better Beamer attached.....