Hi Matt. Thanks for the response. 
My line of questioning is mostly due for my education and not to question 
your abilities or your identification of what you saw. Over the years, I have birded 
with many people with many opinions. There have been many people with the 
same opinion that I have had in reference to the Yellow-bellied flycatcher vs. Acadian. 
Which is another reason for my questioning you about this.  
There hasn't been a Fall season up here at Turkey Point that I recall where
 I haven't had a Empidonax Flycatcher that grabbed my attention for the simple fact
 that of all the field marks you mentioned. While I agree with you about using one field 
mark being a big down fall of many birders, its not like we are discussing hawks vs. warblers. These birds can
be so closely marked that in my opinion some are just impossible. That is why I asked. I also 
find it interesting that the number of Yellow-bellied reports increase in the fall. Of course it could
be as simple as a different route in fall migration compared to spring migration, 
and because of nesting there is just more birds. I wonder, does anyone else ask the 
same question as this? Is there an answer for this. Did you notice a difference in banding in
the spring compared to the fall?

There is no doubt that a bird in the hand alive, looks different than a bird dead in a tray. 
I see allot of overlap in many Empidonax Flycatchers and I simply 
leave them alone. Other times some birds are so clean and marked so well that I am
confident about making the call. How can I be certain what I am identifying is right 
with these 2 birds. Is the difference that noticeable between the two?  I will be checking 
out Kauffmans, thanks for the recommendation.

I would love to have you up to Turkey Point for a nice fall migration day. 
Right now Turkey Point is Packed with flycatchers. Between now and the 
second week of September is real good up here. You should check it out.
Thanks very much for your input. Please consider coming up.
Sean McCandless