While the latest entry in Canon's midrange consumer dSLR lineup doesn't inspire much excitement, that's not really the point of the EOS Rebel T6i (aka the 750D everywhere but the US). It remains a reliable option for people looking for a functional camera capable of handling pet photography, kids' soccer games and vacation snapshots.
In photo quality it doesn't compare favorably with competitors, but unless you make side-by-side comparisons you probably won't notice or care. It's faster than previous models, both for viewfinder and back-display shooting, and gains Wi-Fi connectivity, both of which make it more attractive than its predecessor and worth a look if you're thinking of upgrading from an older model.
Though they have notably different body designs, the T6i/750D and its more expensive sibling the T6s/760D are ultimately only slightly different. The T6s' controls and layout are designed to appeal to a higher-end photographer, with advanced conventions like a top status LCD, lockable mode dial and a lockable control dial on the back, with hopefully less cheap-feeling buttons.
You can find the T6i at about $750 for the basic kit with an 18-55mm STM lens (£500, AU$1,000), the same price as the body-only version in the US and UK (body only is roughly AU$50 cheaper); the kit with the 18-135mm STM lens costs about $950 (£740, AU$1,300).
The T6i's photo quality and video quality are fine in good light -- not best in class, but unless you compare side by side you probably won't notice that they're less sharp or that there's less detail in highlights and shadows.
Noise isn't the T6i's worst enemy; tonal range is. Noise always increases with ISO sensitivity, and in the T6i's JPEGs the noise reduction jumps between ISO 800 and ISO 1600, where you start to see color noise and smoothing. Depending upon lighting, the scene and how large you plan to display them, you can probably use the images all the way through the ISO 25600 expanded setting.
But the bigger problem is that you start completely losing detail in blacks as exposure decreases. The default Auto Picture Style increases contrast a lot so in low-light JPEGs the shadows clip to black, but even in the raw files there's not a lot of detail captured there compared with similar cameras like the Nikon D5500.
A lot of consumer cameras display non-neutral automatic white balance, and the T6i is no exception; it has a somewhat purple bias, so there's some hue shift in reds/oranges. However, one benefit of this is that low-light shots don't have as severe a yellow cast as you'll see elsewhere.
Video has the same issues, namely color cast and a fairly limited tonal range, but otherwise it looks pretty good; certainly good enough for family vacation videos. There's some jello if you're shaking at all (which is typical), but otherwise no notable artifacts.
Canon offers some really cheap, fast lenses optimized for the sensor-based autofocus in the camera, like the 50mm f1.8 STM ($126, £100, AU$200) and 24mm f2.8 STM ($150, £150, AU$250) which I shot with in addition to the 18-55mm kit lens, but let's just say you get what you pay for -- and the 50mm is much better than the 24mm. You'll get your nicely out-of-focus backgrounds, but they both suffer from serious fringing and neither is particularly sharp (or image stabilized).
Canon finally ramped up the performance on the Rebel, including an increase to 19 autofocus areas from 9, and now it's quite good. While it takes a surprisingly long time to power on, focus and shoot -- 0.9 second -- it's competitively fast for everything else. It takes 0.3 second to focus and shoot in both bright and dim light, though in darker conditions (lower than typical living-room light), it takes a lot longer to focus. It also takes 0.3 second for two sequential JPEG or raw shots. Two sequential shots with flash increases to 1.2 seconds.
It can sustain a burst of more than 30 JPEGs at 5 frames per second, and I found the in-focus hit rate is good enough for typical kids-and-pets photographers. The raw continuous shooting is a little more disappointing; it's really fast for 6 shots -- 6fps -- and then tanks down to about 2.4fps. However, you can continue shooting at that slower speed for more than 30 shots. It doesn't simply stop.
Live View (using the LCD rather than the viewfinder) performance is better than previous Rebels, but it's still slow. In both bright and dim light it takes 0.6 second to focus and shoot, and two sequential JPEGs run 0.7 sec.
The multi-point autofocus -- the setting where you let the camera make all the decisions about what to focus on -- actually seems a little more intelligent than most, in that it doesn't always opt for the closest element in the scene. However, like all complete autofocus modes, it's inconsistent, focusing on something different each time you half-press prefocus, even if you don't move the camera.