I want to tell you a couple things about the 7D before you even ask about them because I'm sure they will come up.
The first is that the 7D has a slightly more aggressive AA filter which means your images will be a little less sharp than you T5i. You will want to incorporate some basic sharpening in post to your workflow.
Next, the AF sensor is a little different and causes problems for some people. Basically, the area of AF sensitivity extends well outside the actual square in the viewfinder and if something is closer withing the radius of the AF sensor it may focus on that instead of the intended place. This is by design and not a flaw. In action shooting with things moving, it pays to have the additional sensitivity because with long lenses it can be tough to land right where you want it. But when shooting things that are closer with really wide apertures, it can throw you off if you aren't watching for it. Once you know about it, it's really easy to deal with and after a short time you don't even think about it. But for those who aren't aware of it, it can cause a lot of confusion. Here's a bit of detail on it.
The updated firmware can be had here. http://www.usa.canon.com …eos_7d#DriversAndSoftware
When shooting in low light with a slow lens, your fps can slow down. You may only get 3-4 fps - even in full manual mode. This is a little pet peeve of mine. The reason is because of the metering. There's a lot of debate as to WHY the metering gets in the way even in full manual, but none of that changes the fact that it happens and it's annoying.
Finally, and this may be the case on other bodies as well, but when you are using the pop-up to control off-camera E-TTL, the pre-flash which controls them can still have a minor effect on exposure. If you are doing something where it is really important that your off camera flash is the only source of illumination and you are close to the subject, you may want an ST-E2 or you may just want to use an E-TTL cable.
I am serious....and don't call me Shirley.
Canon 7D and a bunch of other stuff