1D cameras for walk-around and traveling

[BaconBets]

To me, the obvious question is - 'why do you want to buy a 1Dx for walking around and traveling?'
You've already stated that money is a concern. Unless you already have all the flagship lenses why buy a flagship body?
The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.
Unless you work for Sports Illustrated or National Geographic, the 5d3 will be plenty...and the form factor would actually be better for traveling and walking around.
Then you'll have some extra cash for a pocket cam, lenses, and plane tickets.

[briansquibb]

I took my 1D4 on my motorcycle holiday in September with just the 70-300 and 24-105. Was small enough to go in the box on the back plus gave some tremendous action pictures.

[CanineCandidsByL]

As a plus, if it does attract unwanted attention, that much easily grip-able mass should do some excellent damage...make sure to get the warranty .

[neuroanatomist]

The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.

Plus two stops of ISO (although time will tell if that's really just two stops of noise), interchangeable focusing screens, more customization, more than double the shutter life, faster X-sync speed, bigger viewfinder, AF point-linked spot metering, and a much deeper buffer for continuous shooting. 

[briansquibb]

The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.

Plus two stops of ISO (although time will tell if that's really just two stops of noise), interchangeable focusing screens, more customization, more than double the shutter life, faster X-sync speed, bigger viewfinder, AF point-linked spot metering, and a much deeper buffer for continuous shooting.

5DIII has point linked metering

[neuroanatomist]

The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.

Plus ... AF point-linked spot metering...

5DIII has point linked metering

Really?  Care to provide a reference for that?  Because the Canon USA 5D Mark III specs page states:

Metering Modes
Max. aperture TTL metering with 63-zone SPC with the following selectable modes:
(1)   Evaluative metering (linked to all AF points)
(2)   Partial metering (center, approx. 7.2% of viewfinder)
(3)   Spot metering (center, approx. 1.5% of viewfinder)
·AF point-linked spot metering not provided.

[wickidwombat]

The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.

Plus ... AF point-linked spot metering...

5DIII has point linked metering

Really?  Care to provide a reference for that?  Because the Canon USA 5D Mark III specs page states:

Metering Modes
Max. aperture TTL metering with 63-zone SPC with the following selectable modes:
(1)   Evaluative metering (linked to all AF points)
(2)   Partial metering (center, approx. 7.2% of viewfinder)
(3)   Spot metering (center, approx. 1.5% of viewfinder)
·AF point-linked spot metering not provided.

 
damn got my hopes up that it might have spot metering AF linked

oh well

[briansquibb]

The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.

Plus ... AF point-linked spot metering...

5DIII has point linked metering

Really?  Care to provide a reference for that?  Because the Canon USA 5D Mark III specs page states:

Metering Modes
Max. aperture TTL metering with 63-zone SPC with the following selectable modes:
(1)   Evaluative metering (linked to all AF points)
(2)   Partial metering (center, approx. 7.2% of viewfinder)
(3)   Spot metering (center, approx. 1.5% of viewfinder)
·AF point-linked spot metering not provided.

mmmm - interesting because at the Focus on Imaging show we asked that very specific question from the Canon tech rep and got a yes it does. My friend bought a 5DIII on that basis as he is heavily into macro shooting. He will be very disappointed if that is not the case 

Another good reason to keep the series 1 then

[BaconBets]

The main difference between the 1Dx and the 5d3 is crazy fps and metering, and weather sealing.

Plus two stops of ISO (although time will tell if that's really just two stops of noise), interchangeable focusing screens, more customization, more than double the shutter life, faster X-sync speed, bigger viewfinder, AF point-linked spot metering, and a much deeper buffer for continuous shooting.

Neuro, I wouldn't call any of that critical for "walk-around and traveling"
There will not be 2 stops advantage in RAW...not even close.
And for his purposes, by the time he burns up that shutter, the 5DV will be out anyways.
Would you really advise him that this is this best choice when he has specifically said that he will not have any money left to spend on photography gear? (And he is concerned about the size/weight)