What reasons would you choose full frame over crop - vice versa?

I just wanted to know your guys answers to this:

What reasons would you choose a full frame camera over a crop?

Or

What reasons would you choose a crop over a full frame camera?

For the purpose of this thread, I'm going to choose two cameras. One crop and one full frame, to give your reasons on. The reasons i'm choosing the two cameras is because anyone can round off benefits of a 5D mk III vs a 60D.

Crop sensor - 7D

Full frame - 6D

I chose these cameras as the 7D is the highest grade crop sensor camera, yet the 6D is the lowest grade (cheapest) full frame camera, with still great specs. Also these have a smaller gap in price to any other recent releases.

Choose your camera choice in the poll and give reasons why you chose it

PS. It's just for abit of fun, also research for me to see how photographers differ.

EDIT: The question i'm asking is simply this: If you had enough money to buy a 6D or a 7D as your one and only camera, which would you buy and why?

Crop at one time was in my bag for reach.
Now they just cram too many Mega Pixels and the pixel pitch is too small for quality images.
Less than 5 microns is a killer.
You can crop more on a FF than Crop APS can reach.
If the 7D had 12 or so MP that would change my mind.
So its dual FF all the way in my bag ... 5DC and 5D M II
and this poll should ask FF or APS instead brand and model.

7d. I shoot a lot of birds with a 400mm lens, crop gives me a tighter field of view - I'd need over 600mm to get the same thing with full frame.

Your poll is strange. not going to choose

Why would I go FF or crop?

crop- when I absolutely need the reach

ff- everything else

I'm a proud owner of a 7D, but I picked the 6D because I'm in "want" of a "FF"

Two reasons:
*Better Low Light Noise <<< But maybe ML could fix this for the 7D. (have not tried it)
*Better Sensor IQ (greed) or should I say Picky!

But to set this off straight, when I am ready to purchase a full frame.
I will do so and still keep my 7D.
There is just some things you can't live without from a "crop sensor".

I shoot full frame because:
Bigger brighter viewfinder
My lenses are the same FOV as when I shot film. No 1.4 multiplication.
Much cleaner with less noise.
I can print larger

I do own a 40D but its just a backup.

For sports, action, birds etc, I would choose 7d
For all other stuff I would choose 6d

I would pick the 6D for the higher iso capabilities and I would pick the 7D for the speed and higher pixel density since I like shooting wild life.

For my own personal wants/needs I would skip on both and wait for the 7D Mark II which I plan on doing. With that said I already have a 5D3 to compliment it.

Gregg.Siam wrote in post #15495391
Your poll is strange. not going to choose

I'm sort of in this space. It is a very strange question. Both have their uses and both are needed. One is not a replacement for the other. I choose my crop when shooting wildlife, sports, any action, macro (most of the time), or when I get a hankerin' to shoot with my 17-55 or 100-400, or sometimes just because I feel like it. I choose my FF when shooting portraits, when I want wide (17-40), when I know I'll be shooting at ISO 6400 or above (there is not a big difference between ISO3200 and below), or when I have a hankerin' to shoot with it. I really don't pay a lot of attention to which I grab, but I too will not choose as there is no clear choice.

bobbyz wrote in post #15495449
For sports, action, birds etc, I would choose 7d
For all other stuff I would choose 6d

Don't put this in people's head Bobby lol...

I have not shot, not 1 Bird, or 1 sport, or anything etc with my 7D.

I believe any DSLR now adays can shoot any Genre.

You might need to spend a little more on accessories though

Gregg.Siam wrote in post #15495391
Your poll is strange. not going to choose

I concur

Different tools for different jobs.

FF for quality.

DreamMaker23 wrote in post #15495474
I believe any DSLR now adays can shoot any Genre.

This has always been true. Each can shoot everything the other can, however, each has an area where it does better than the other.

I've grown fond of the full frame aesthetic, low light capability and getting wide shots from wide lenses. I do miss the extra throw but that's what teleconverters are for.

I don't think this poll is that strange due to the price point being so close.

The major difference for me given the choice would be the dual processors and speed of the 7D. Higher burst rate is important to me.

Though the newer generation sensor and processor in the 6D will yield better pictures with less noise. Plus the wifi and in-camera HDR are cool.

Not such an easy choice! Get both!

it just depends what you shoot
I need reach so a 7D is perfect