I shot with a pair of 7D for five years and made around 300,000 images with them. They were fine cameras, but I finally updated to a pair of 7D Mark II about two ago, have been using them ever since and taken around 100,000 shots with them. 7DII are a very good, solid upgrade from the original 7D and the best APS-C "sports/action" camera Canon makes.
But the 80D is well worth considering, too.
Not surprisingly, 7DII (and 80D) do not match current & recent FULL FRAME cameras for high ISO performance. However, both are much better than the original 7D (which was pretty good for it's day). 7DII and 80D are pretty equal in high ISO performance, I'd estimate they both deliver roughly one and a half stops higher usable ISO than original 7D. The ISO range of both 7DII and 80D is 100 to 16000 (expandable to 25600 and 51200), compared to original 7D's 100-6400 (expandable to 12800). You'll have to judge for yourself how usable higher ISOs are... I've used original 7D up to ISO 6400 (with additional post-processing)... I've used 7DII at ISO 8000, 12800 and even 16000 occasionally. Below is a test shot done with
7DII at ISO 16000...
Above was shot RAW (CR2) with no in-camera noise reduction and with minimal (default NR) during conversion in post-processing using Lightroom 6. Lighting was a single 60 watt CFL bulb and a small window, both about 8 or 10 feet from the subject. As you can see from the enlarged detail, there
IS some noise at ISO 16000... But I think it's pretty well handled. It also can be further reduced with more sophisticated NR (I sometimes use Noiseware plug-in with Photoshop... but didn't for this test shot).
80D is year and a half newer model with a somewhat higher resolution than 7DII (24MP versus 20MP... and 18MP in orig. 7D). 80D also is not as well sealed for weather resistance or rated to be as durable (100K shutter rating versus 200K... 150K in orig. 7D). And 80D has slightly slower frame rate: 7 frames per second with 80D versus 10 fps with 7DII. (Original 7D was rated to be able to do "up to 8 fps", but tended to slow for AF and metering often... To me the 7DII seems a lot more consistent with it's high frame rate. I haven't compared 80D.)
The 7DII's buffer is able to handle over 30 RAW files. 80D can buffer about 25 RAW files, similar to original 7D. Keep in mind that 80D's images are about 20% larger on average, so it probably has about the same size buffer as 7DII. All three cameras can handle upwards of 100 JPEGs before they need to slow or pause to clear the buffer (assuming orig. 7D has firmware 2.x update, which greatly increased it's buffering capacity).
80D's 45-point AF system in some ways is an upgrade from 7DII's 65-point, and in other ways a downgrade from both 7D 19-point and 7DII's AF:
- 80D has up to 27 f/8 capable points versus one f/8 point in the middle with 7DII (none in orig. 7D).
- 80D has four focus patterns: All Points/Auto, Single Point/Manual, Large Zone, Small Zone.
- 7D Mark II had seven focus patterns (up from five in orig. 7D). 7DII has same four as 80D, plus: 4-point Expansion, 8-point Expansion and Spot/Single Point (high precision).
- 7D Mark II uses a discrete chip to run the AF system, similar to 1D series (and orig. 7D). This is in addition to dual image processors. 80D uses a single processor for everything.
7DII has a "joystick" to control AF point selection (as does orig. 7D), while the 80D uses a multi-directional pad. 7DII improves on original by having an AF pattern selection collar right around the joystick, rather than having to use a combo of two buttons the way AF pattern selection is done on 80D and orig. 7D. The secondary controls of the BG-E16 battery grip for 7DII also now includes a secondary joystick (not found on 7D or 80D battery grips).
80D is slightly more geared toward automation with Scene, Creative Auto, Creative Filters, No-Flash modes (not nearly as much automation as the Rebel series cameras, thoug). More pro-oriented 7DII lacks those and has additional user-customization options. Of course, like all Canon DSLRs, both 80D and 7DII have M, Av, Tv and P for greater user control. Both also have Canon's "A+" super automated "point n shoot" mode.
80D is a little more video oriented. Alongside the 8OD, Canon announced an accessory shotgun microphone and an optional Power Zoom module uniquely usable with the new EF-S 18-135mm IS "Nano" USM lens, which a;sp was introduced at the same time. (Of course, that lens and those accessories can be used with 7DII too, as well as other camera models.)
7DII has a PC flash sync socket... 80D doesn't. 7DII uses wired remote switches such as RS-80N3 and TC-80N3. 80D uses the RS-60E3. Both utilize the same RC-6 wireless shutter release.
7DII has dual memory card slots... one SD and one Compact Flash. 80D only has a single slot for SD memory.
80D has an articulated rear monitor with Touchscreen control. 7DII's rear monitor screen is fixed and is not a Touchscreen.
Both cameras have Dual Pixel AF in Live View (which was introduced in 70D and is much faster than the contrast detection AF in 7D/60D, etc.)
Both cameras have Flicker Free feature, which works great to improve exposure accuracy under fluorescent and similar types of lighting.
Both cameras have 100% viewfinders.... 7DII's has slightly higher magnification (1.0X versus 0.95X in 80D).
80D has built-in wireless connectivity. 7DII doesn't, but it can be added with an inexpensive W-E1 module that fits into the SD memory card slot...
OR a WFT-E7A Wireless File Transfer module that offers much greater range and faster WLAN data handling.
80D doesn't have built in GPS. 7DII does (but it tends to draw heavily on and rapicly drain the camera's rechargeable battery). Canon GP-E2 GPS Receiver or other accessory GPS device may be used with 80D (all with their own, separate power source).
Both cameras use the same LP-E6N type battery (older LP-E6 work fine, too). 80D is rated to be able to do around 40% more shots per charge (but a lot of the difference may be due to 7DII's GPS, which can optionally be disabled to save power).
So... you have choices: 80D for a little less money if it meets your needs... 7DII for a bit more $ if needing it's generally higher performance and durability... or maybe full frame Canon? 6DII itself isn't a whole lot more $ than 7DII.... but, depending on what you have to use on it, may mean add'l cost of lenses.
Hope this helps!