Canon EOS 7D MK2

Dave - I think that I do understand the current generation of Canon sensors.

I've use a 7DMkII extensively, mainly for low light, indoor work (and for that matter also nearly all of the 5D Series, but I have not used not a 6D). That's why I wrote:

"The 7DMkII is going to provide a better High ISO performance than your 550D, however as noted the 6D is reportedly better again." (Post #7)

I don't have a passion for shooting BIF, but I have seen (and also commented on) some of you great BIF images - and I am sure that you do routinely use 3200, 6400 and 12800 and get great results.

But all of that does not incline me to step away from the concept and the practical results of:

"even if a camera has good figures at ISO 12800 - the odds are that the cameras figures and the resultant images will be better if shot at ISO1600." (Post #15)

WW

Well duh, WW. Any sensor should do better at ISO 1600 than 12800. I'm saying that the results, after noise reduction, can be excellent. At f/4, ISO 6400 will generally be sufficient.

I respect you also and enjoy many of your posts; however, I think that the OP will be very happy with a 7D MkII in his stated usage. I assumed, perhaps wrongly, that he had his eye on a used sample. (At this point in the 7D2 life cycle, I'd highly recommend buying used. Same for the 6D. I wouldn't suggest to anyone to buy either new). In the Canon line, for his stated usage, the 5D MkIV will not be beat. Here's one from last week at ISO 12800:

Rose Window by David Stephens, on Flickr

Why futz around with a crappy 6D, when you can buy a $3500 body, a $1,000 lens and shoot at 12800 with abandon? Who knows, the OP may have an open ended budget.

... Paris? Notre Dame? very nice.

Yes. Thanks.