Here's what has happened from my perspective. While I appreciate and value the feedback regarding improving technique and processing and all that, and I need to learn an awful lot, I've gotten very distracted by the fact that my hardware seemed to be selling me short.
This is partly because it was only due to some inheritance that I could ever have dreamed of buying this level of equipment and there are/were other higher priorities. Unlike some in my shoes, my wife actually pressed me to make the purchase, practically insisting I get the 5D3. The 6D saved $$ on the 5D3 that went into the 24-70 F4 since I backed away from that beautiful 100 macro. I had visited the store I purchased from, testing these things out extensively, especially the 300F2.8 and extenders and both my much more experienced friend and myself were not that impressed (he's going to make a purchase very similar to mine and shoots with a couple a D300's presently).
After the purchase I actually returned the first 6D/24-70 kit for a second after shooting test shots like crazy that week. The 300 of course was thrilling me because we all know it's not trash but that nagging remained that I wasn't getting what I should. Through extensive emails with Canon Canada a very nice representative by the name of Mike suggested I ship the stuff in, which I immediately did, adding a CD of some shots and an impassioned plea that they address my concerns.
And now I am going nuts worrying that they might do the bare minimum and I'll be stuck. I fully agree that high level photography is an art that depends on the shooter, not the equipment and I'm not interested in bragging about equipment or bettering others because of it. It's just that I'm one of those people who has been raised to always "do your very best" and I fuss way too much about such things.
Cropping is of course something I've been doing for a year and one of the reasons I hoped for a 600mm reach for birds in particular, compared to my Nikon D5100/70-300, 450 field of view. I've left photos untouched thinking that would give you folk a better idea of what I was dealing with. At the photo shop I did shots with the D5100 and compared to the 6D and there wasn't a huge difference. Then I read everything I could get my hands on regarding crop sensors and apparent reach and pisel pitch and realized that regarding resolution of detail 18 MP crop and 20 MP full frame are pretty similar. That's not to equate the IQ in general since the 6D is obviously a step up. Of course this led to pixel peeping and reading all the D800 reviews and all that fretting and fussing and here I am on this forum continuing!!
Not to mention birds arriving for spring and the pending lake thaw that will see me out on the water with the ........ oops, I may be out with the used 40D I just got for $200 and my 70-300 F4-5.6 IS, which is right back to the D5100 realm I was leaving behind. Canon claims a 10 day turnaround so maybe there is still hope (I've allowed 1 month and am working on a tree mount tripod setup etc., trying to use my time to advantage). So that's the whole nine yards and why I'm anxious for feedback from others who have the same equipment.
Sorry for this getting so long.