Flsun V400 High-Speed Delta 3D Printer - 600mm/s Printing Speed, All Metal Direct Drive Extruder, 300℃ High-Temp Nozzle, 11.8"x16" Build Volume - Save 85% Printing Time for Rapid Prototyping, DIY Projects & Home Manufacturing

First and foremost: if you decide to buy this printer—highly recommended, bee tee dubs—make sure that when you go to autolevel the system, you put the STICKY SIDE UP. It clearly says it on the protective sheet you peel off, but it seems very counterintuitive. Again: PUT THE STICKY SIDE UP FOR AUTOLEVELING.That said, my experience with 3D printers goes back to around August of 2016. My very first printer was a third-generation 3D Systems Cube printer. It wasn't great. Second printer was an Anet A8. This was a step up in quality, but took hours to build and nearly caught my house on fire. With that (upgraded) system, I printed parts for a VORON CoreXY system. Finally, I decided I wanted to try a delta printer, so I got the Sintron Kossel Mini.Two and a half years after getting the Sintron delta, and it's still not working properly, despite various upgraded parts. Delta machines require a great amount of tinkering and finessing to get them working correctly, and not a small amount of maths for that tinkering and finessing to be worth anything at all. Because of this, I was hesitant to get the FLSUN QQ-S, but decided to bite the bullet and give it a shot.What I Like:- The printer was delivered in pristine packaging and each component separated from the other components.- The build process was swift and intuitive, with the directions (I opted to see how they fared in comparison with the Sintron's hijacked guide) causing me some grief only once.- Setting up the printer to actually print from that point was incredibly easy, though I've got my qualms with the wi-fi implementation (more on this in the "What I don't like" section).- The included microSD card had a few different files, including manuals, software, firmware, and a few test models for you to print.- The touch screen is pretty responsive and a massive step up from my other Marlin-driven printers and their touch knobs.- Loading filament is very easy, with the steps laid out clearly in the instruction manual.- Having an actual power button is, to me, a novelty (other than the Cube, my other printers either only have a simple switch, or nothing at all).- It's a very quiet system by comparison of my others, though the always-on cooling fan for the control board/PSU area always being on even when not in use is frustrating.What I don't like:- One of the corner covers absolutely refuses to accept a screw easily to secure it to the frame. Not entirely sure why, but no amount of prying will fix it. This is just cosmetic, though, and doesn't affect anything other than my own personal sensibilities.- The three test files they include on the microSD card are VERY large. I would've rather seen the typical XYZ calibration cube and 3D Benchy as the offered files, as they can be printed in a very short amount of time to more quickly allow you to appreciate the printer.- Also for the models: they were sliced in such a way that the printer takes its time with them. Though this is great for the quality of the prints, as they ARE on the large size, you're gonna be there for a while.- The QQ-S has wi-fi as an advertised feature, but you can't natively connect to it over wi-fi without a special app that allegedly doesn't even work (haven't bothered to check, and won't—I'm opting for the OctoPi route).- The end stop cables have a lot of extra slack and need to be secured to prevent them from being caught in the belts. Hasn't happened to me yet, but I'm gonna take steps to make sure it doesn't in the future.All in all, I'm very satisfied with this purchase and with the printer itself. I'll be hanging on to the packing materials for a couple dozen prints in the event it decides to fail in some way, shape, or form, but so far in a couple days of use, it's a beautifully designed machine that's ready to go within twenty minutes or so of opening the box.For slicing software, I just went with the most current version of Cura from Ultimaker, as well as trying my hand with Simplify 3D. Cura worked pretty quickly using the built-in FLSUN QQ profile, as did Simplify 3D with the profile of the same name.For the prints attached, I opted for a print speed of 120mm/s, and the system had no problem with this speed, though the infill suffered from under-extrusion as a consequence. I've read in the FLSUN QQ 3D Printer Owners group on Facebook that swapping out the stock hotend for a genuine E3D v6 is a pretty straightforward procedure, so I'll be doing that this evening to see what kind of improvements that yields.10/10 would recommend.