I agree that it depends on who is doing the work. With all the stencils available for air brushing fish, if you have somebody skilled with an airbrush, it will look awesome. I have seen replica fish that looked like you could put in water and it swim off. And I've seen some that looked like you had handed a 4 year old the air brush and turned them loose. There's some on eBay that look down right scary. It's all in who is doing the work in either case, that will make it look good or like crap.
I suggest looking at the McKenzie and Wasco taxidermy websites or getting their catalog sent to your house....see what forms and mounts are available for your fish. You might be surprised to see that your skin mounts are about 90% fake/replica anyway....fake eyes, gills, fins, etc.