Upgrade to 70d or 760 d ?

[Luds34]

If you're upgrading from a Rebel, and the 70D is an option, then get the 6D because it's only a bit more expensive and infinitely better if you're just doing everyday stuff.
Heck, I do ok shooting BIF with my T3! (cheapest body they ever made) so the 6D is gonna be good enough.

Is it? I guess it depends what you mean by "everyday stuff". But other then having a full frame sensor the 6D seems inferior to the 70D in many ways. Some big ones just off the top of my head:

Max Shutter Speed
Max Flash Sync Speed
Focus System
FPS

I would argue that the 70D is one of the better (on a realistic budget) jack of all trades cameras on the market. I think the OP talked about tracking kids running around. While I mostly use just the center point focus point, it is nice to move to the top points and use ai servo to track at the face/head level for better framing of a subject in motion. The 70D, used in this manner, tracks very well. When I have tried the same with a Canon camera using outer points that are not cross type, it misses much more then I like.

 

[Calaverasgrande]

I bought the 760D about a month ago. It was an upgrade from a T2i.
I got a great deal from a certain HK dealer that also produces humorous youtube vids about photography.
It is much better than the T2i and most recent Rebels in terms of IQ, esp low light.
It also is quite fast. The 5fps is no joke and seems to not be affected by metering choices and AF the way the T2i was. So far the battery is pretty darn solid. I have yet to run it down from a day of street shooting. But I never use flash either.

Negs;
there are not as many top plate LCD buttons as other Canons with a top plate LCD.
It takes a very new battery (I think the M3 uses it too?) so there are no 3rd party batteries or chargers yet.
Ditto for grips, only the Canon battery grip for now. So no nifty grips with intervalometers built in.
Also no headphone jack, and no way that I have found to see adio meters while shooting video. So it is easy to get bad sound on the video.
Positives.
It focuses pretty darn good. The ability to switch modes in VF, move a zone or a point manually is great. It locks pretty good. Though I do get some hunting with some lenses when there isnt enough light or contrast.

Yes you can back button focus on this model.

 

[troy19]

Just a quick update to this topic:

I rented a 70d with EF 2,8/17-55.

Body felt good, no usability problems when coming from a 400d, but much more settings to be done for fine tuning.

Lens didn't convince me at all. I had high hopes because the lens is well regarded as a good performer, but sharpness was below my expectations.

So I got a 70d with Sigma 1,8/18-35 Art and this is a great combination. AF is snappy and lens is very sharp. That's a huge step forward in my little photo world

Combination though had a pretty obvious front focus which was easily corrected by the 70d's afma.

And here we are at the point that was the main concern when deciding between 70d and 760d. I wanted to make AF working fine with all lenses, the ones I have by now and the ones I will add in some time. So decision was easy at the end.