There Are Pandas, and Then There Are Pandas.
And this isn't either of them! The Pandas we're talking about here, are watches, not bears. And what got me thinking about them (again) was a link posted this morning by @cm.rook who pointed a few of us to the very attractive (and not terribly priced) Yema "Rallygraph" Panda which, in it's most traditional arrangement, looks like the one on the left, but can also be had in the version on the right: The model on the left is a true Panda, while the model on the right is called a reverse Panda. The reason for that distinction is clear--Panda bears, only come in the first arrangement. Now at this point, everyone should be thinking about the most well-know Panda, The Rolex Panda, which is actually a Daytona, and among Rolex Daytonas, the most famous of which is the Paul Newman Daytona, which was famous first, because it was Paul's, and second because it sold at auction for $17.8 million (US Dollars). The story of that auction is well-known so I'll only...
Nov 8, 2019
That said, One thing that Canon has going for it is volume. Because they sell so many cameras and lenses, they have the largest budget for lens R&D. Thus, they have the widest variety of niche lenses. If you're a pro, or if you need an odd lens for whatever reason, this can be a big deal. Canon's DSLR's are also generally very good at video (something Nikon is terrible at).
Historically, Nikon has had better AF systems, particularly with regards to tracking. My recollection is that dpreview's tests show this to be the case with the latest pro AF systems as well. Their sensors are also usually top of the line, and often outperform Sony's DSLRs, even when both are using Sony sensors. Nikon's lenses are generally excellent, but they seem to focus too much on kit-zoom type lenses. Prices are also usually higher than the competition. UX seems to be poor? At least according to Thom Hogan, and it's his brand of choice.
I don't really know anything about Sony, except that they put very good sensors in relatively cheap bodies and their pro glass is excellent, even if it isn't actually made by Zeiss. As a practical matter, I think the priority should be placed on glass, meaning you should choose whichever mount has the lenses you want to shoot with, though it can be hard to know what lenses you want before you've already committed to a mount (my needs have certainly changed over the years, but I've always stuck with the F-mount).