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
I was in the same camp to say "always invest in your glass first." However, that's no longer true. The newer high pixel count sensors, specifically, the 40MP+ sensors on the Nikon D850 and Sony A7Rii and A7Riii really exposed some of the short comings of some of the older lenses. I believe there is a review floating around the internet somewhere detailing about how some of the Nikon lenses felt obsolete. So if you decide to invest in more glass, keep this in mind. There is no silver bullet to say any lens design would always stand through the test of time.
With the advancement of digital technology, there are so many things that modern body can do. Some of the features I love and look for are things like: 1. Stablization, whether it's in-body stablization or the availability of lenses with built-in stablization. Better yet, hybrid stablization, look at Olympus, Panasonic, and Fuji for example. 2. Edge to edge AF points. This just allows for way more freedom in composition. 3. Focus peaking and live view magnification. This is for manual focus, focus peaking is especially nice because it allows for fast manual focus when you are shooting objects that might be moving. 4. Eye-AF from Sony. The Eye-AF in the third generation Sony cameras are simply amazing. It just makes any portraiture work much more enjoyable. 5. Fast AF, cameras can always do better in this regard. Even the D750 have some predictive algorithm when it tries to focus on moving objects, doesn't really work that well all the time, but better than nothing.
My suggestion would actually be to look at what kind of technology is available, what you think would be essential, then make a decision on whether you want to stay with Canon or not. The T3i is a pretty old body now that almost any upgrade to it would be a huge upgrade in every way.