Purchased 6D, encountering metering issues?

I don't have a 6D, but I too do not understand what Canon does with its DSLRs. Ever single Canon compact I have had meters better (and does better in green box and P or auto ISO modes or choosing appropriate SS, Aperture and/or ISO). Now granted, they are metering off the sensor itself, but still it seems weird to me.

It's nonsense to suggest that decent photographers that use DSLRs should only be shooting in M.

I found that I needed +1/3 stop indoors when at high ISO for the 6D. Outside, I don't need exposure compensation, unless the lighting involves lots of sky, etc.
The 6D auto white balance struggles with fluorescent light, and I need to use a custom while balance. Incandescent lighting requires setting the camera on the incandescent while balance setting, and then the results are great.
It is a good idea to try a shot or so indoors, to see if it would help to modify exposure or white balance.
Frankly, my immediate, first reaction was that exposures were more reliable with the 60D than the 6D. I suspect that the wider view plays a role, at least for me. I went from crop to full frame.
I use TV more than AV.

I've recently added a 6D and have had similar experience. The 7D meter is much more consistent, the 6D in some situations (heavily backlit) is very difficult to get correct exposure with first shot. I may need to send mine in for evaluation, sometimes I'm getting no difference in exposure reading between spot and evaluative.

I don't quite understand the lack of consistency between camera bodies. We shouldn't require an alternate technique. Pretty frustrating.

Bought a second 5D Mark III yesterday with Firmware 1.3.3.
Compared to my first 5D Mark III Firmware 1.2.3 there is about a 1/3 to 2/3 stop difference. My two 7Ds with different firmware are both the same exposure
It seems my first Mark III 1.2.3 is underexposed compared to my new Mark III 1.3.3 and the 7D's
70-200 lenses mounted on tripod.
All four bodies set to M, ISO 1250, f/2.8. Spot metering, shooting to Lastolite target Gray card. WB Tungsten.
Late last night with lamp lighting.
Exposure at "O"
Both 7D shutter exposure was 1/40
5D Mark III 1.3.3 1/50
5D Mark III 1.2.3. 1/80

Maybe new firmware has something to compensate. Unfortunately Canon USA has not even heard of the new specs of 1.3.3.

There are also calibration differences between two samples of the same model. Only cameras like the 1DX allow you to calibrate this yourself (without changing exposure compensation).

I've had my 6D about 18 months and noticed immediately that it was underexposing 1/3 stop. I shoot RAW, AWB, AV or M. My solution was 1/3 EC and run with it, unless I'm using a flash. I usually bracket 3 exposures 2/3 on either side. This is really a small problem with a simple solution. I also have a 7D that's overexposing 1/2 stop. Same solution, EC adjustment. The auto exposure for subjects against a bright light is somewhat harder to deal with in AV but manageable in M. The longer I have this camera the more I learn.