I've had the 5D IV for about two months ago and have been shooting like crazy with it. My previous body was a very old 20D, so this was quite the upgrade. The tl;dr: for this intermediate to advanced amateur, this is an incredible body that has been a joy to shoot with and well worth the cost.THE OUTSIDE:Starting with the mechanics of the body, this thing is built like a tank. I bought a battery pack along with the body and installed the pack and two batteries immediately after unboxing the body. This setup is quite hefty but built like a tank. I'm a bigger man so I don't mind carrying this body around for large periods of time - even with a Canon 70-200 2.8 attached - but for the more dainty among us, this body may be unwieldy for long photowalks or events. The textured grip is wonderful and provides a nice, rubber-like feel that makes handling the extra weight easy - I can easily hold the camera, battery pack, two batteries, and an attached 70-200 2.8 with one hand with little concern that I'm going to drop it. All of the buttons have a nice tactile feel, and the main click wheel on the back of the body is much more silent than my old 20D - a welcome improvement. Perhaps my only ""concern"" - which I have quickly adapted to - is the fact the shutter release is quite smooth, and it took a little getting used to without the clear half-way stop to engage the autofocus and metering without accidentally releasing the shutter. I still sometimes may this error. Not a huge problem, but it did take some getting used to.That screen my oh my. I always thought that the touch screens on DSLRs were a bit gimmicky - after all, all I need the screen for is to know what my settings are and be able to quickly review images - but the touch screen is a GAME CHANGER. The ability to create your own ""status screen"" with what essentially amounts to a widget-like system is incredible, and being able to adjust any settings that you choose with a simple tap makes the whole process much simpler. My wife took the 20D, and watching her navigate the menus on a postage stamp-sized screen makes me hurt inside compared to my experienced with the 5D IV. The screen is nice and bright with an incredible resolution and a beautiful color space that makes reviewing images on-the-fly easy to do.The rubber grips covering the ports are solid and stay in place, if not a big difficult to get out of their ""seats"" sometimes.FUNCTIONING:To keep this relatively brief, I'll simply hit the highlights - both good and bad - of day-to-day use of the body in my experience with it thus far.- As mentioned above, the ability to create a custom status screen using widgets is incredible. It's infinitely better than being limited to the top side LCD panel or digging through the on-camera menus to adjust settings. Apart from particularly specialized functions, I very seldom have to dig into the full camera menu. And for that purpose I simply created my own menu with sub-menus to make those settings more easily accessible. Since getting these initial features set up, I have yet to have to dig through the full menu to find whatever function I'm looking for.- Performance across most of the ISO range is excellent. Depending on the image, noise starts to crop up noticeably around 3200. You can easily push the ISO far beyond that depending on the composition. Since I'm shooting primarily with fixed 2.8 lenses, I have yet to come across a shooting situation - even late at night - where the ISO becomes problematic. I've found the auto ISO setting acceptable and only rarely need to override this setting to set a ""ceiling"" ISO for particularly dark shooting situations.- AF performance is similarly outstanding. Compared to the latest mirrorless systems the spread of the focus points across the viewfinder is limited but a huge improvement coming from the 9-point 20D. If you choose to use the live view function, being able to tap to focus on a point - similar to that seen with mirrorless systems - is nice albeit inaccurate and imprecise. Since there are relatively few focus points, the precision of focusing using this setup is pretty poor, and if it's critical that I get pinpoint focus, I will generally switch back to the viewfinder. But in a pinch, the performance in this use case is acceptable.- The two-slot memory card setup is another welcome feature, and you have a fair amount of latitude with respect to how you want to set this up - e.g., duplicating images across both memory cards vs. transitioning to the second memory card once the first is full. I wish both slots were CF rather than one CF and one SD slot, but I can get over it. Another ""wishlist"" item would be even greater control over how files are sent to the individual cards - for example, it would be nice to be able to shoot in RAW+JPG and have one file type sent to one card and the other sent to the second card. Again, a minor point and not a huge deal.- High-speed shooting is acceptable. Of course it's not as fast as the 1DX, but as a non-professional, non-sports photographer, it suits my needs. Even when shooting in full resolution RAW, I rarely hit the buffer limit. When shooting in full resolution JPG, you can shoot continuously at the 7 fps maximum rate for quite a long time.- Boot-up time is snappy - less than a second for the most part from completely off or when in sleep mode.- I do not use and have no interest in videography, so I have yet to take a single video. I've heard that this body sucks for serious videography, not least of which is the ridiculous compression algorithm Canon decided to use for 4K video, but since I have no intention of recording video to any significant degree, this isn't something I care too much about. Based on others' reviews, however, this definitely appears to be a body which is a no-go for serious videography.- In-body wifi: much too slow to use for transferring a large number of images, however using this feature along with my phone to function as a remote shutter is awesome. I don't think this would be usable for a professional setup, but for more casual shooting situations - for example, to open the shutter for a long exposure to avoid the camera shake that occurs with that initial button press - this is a nice convenience.There is much more to say about the body which has been said in other reviews or which can be learned about by watching in-depth review videos, but these are the main points that come to mind based on my use.OVERALL:If you're looking at this body, you probably know what you're getting into and what specific features you're needing in your camera. All I can say is that I love using this body and wholeheartedly recommend it. The price is steep, but with how much more I enjoy using this over the 20D, it has been well worth it.