I was really surprised at what this printer can do. I have 5 of them now and use them for production parts in my valve and machine. I even print sprockets using a chain drive and PC carbon fiber PETG carbon fiber.I have upgraded all of them a bit. All have direct drive extruder and the all metal hot ends, as I print at 248C and the Teflon tube cannot take that temperature very long and will cause a blockage in the hot end.The hottest I have had to print so far is 255 and it works great. You can buy a cheap “heat break” that makes the Creality hot end “all metal”.Three have the dual Z axis kit on them, and the other two still single and print fine. But the single Z's need leveling more often. I put all aluminum extruders on and have no issues with feed. I have never had to adjust the E steps, nor have I upgraded the firmware, as they all work and print parts within .02 mm. The only issue I had was three of them had .4 mm nozzles were not .4 mm, from the factory, and that caused some funny prints with the walls separating. I used a digital caliper and measure the filament coming out of the nozzles at under .3 mm. Now with every nozzle install I run some filament out and see if it, shows 0.4 exactly on all the replacements. All the walls print strong now. I think that Creality got some .3 mm nozzles with .4 marking.To get perfect prints requires some testing and working on the printers. I print almost exclusively PETG and many different brands depending on he price. I noticed that some I bought direct from China were “wet” and so I bought dryers. All the PETG I dry before using and get no “blistering” where the moisture expands under heat. I just don't have time to keep reprinting because of moisture.I also print some TPU and at on time printed over 500 of these “rubber” grommets that our supplier stopped making during the COVID shortages.The main thing is to assemble it correctly so that the X bar is level and the wheels (with the pom tires) can actually spin with some friction. You can measure with a metric tape or rule and get it within .5 mm. I actually drilled a 5 mm hole in the vertical to be able to get the X axis perfect. The hole allows the Allen wrench to loosen the X cross member so you can level it without having to keep removing and adjusting the whole X axis bar.The verticals need to be square to the base and they are very close. On two I put the triangle rods to get it perfect. I used a machinist square to get it perfect. Smooth is the keyword. You don't want any "jump" from the Z axis (rising axis). Parallel and 90 deg to the bottom frames. After about 6 months I installed the dual Z axis and that was simple enough. This one change made it so I can print the same part over and over up to 100 times without having to tram the bed. Also called leveling. `After some time I learned that he Z limit switch will get out of calibration and that spraying it with canned air removes the dirt or whatever is changing the stop point. I think an LED version would be better.On the beds, every one of them has had loose axles on the wheels. The 5 mm screws with 8 mm nuts needed to be tightened. To do this you need to loosen the offset wheels so you can get them vertically stable. There should be absolutely NO wobble in the bed. If you feel any, stop and tighten the rollers. I have had to replace three rollers where the bearings were bad and the wheels wiggled on the shafts. Always adjust the cam 10mm so the wheels can move with slight friction. Over tight causes problems and too loose is also bad. Just so they spin with friction. No wobble side to side or when you lift the corners of the bed.Every screw on the printer needs to be checked for tightness. EVERY screw. Loose screws are a nightmare. Even on my $1000 big printers, all of them needed to have the screws tightened, even the screws under the bed. No wobble and you will have “happy printing”.I have not put the auto bed leveling on as it actually takes longer to print with it (on my other printers). I use only glass on the beds (I scrapped off the magnetic sheet and cleaned with alcohol) and still use the doubled standard printer paper to set the level. I just got “good” at it. Then when the print starts sometimes, but rarely, I will tweak the adjustments. I usually print a skirt with three lines so I can “feel” the thickness of the first layer.I did put the stronger bed springs on also, this gives more stability. I use the Ultimaker Cura (updated)and it has more adjustments than most beginners can use. But as you learn you can make slight adjustments and try them out and see things improve. One of the good things is this printer is so popular you can find lots of YouTube videos to help you. And parts can be found on Aliexpress for the same parts way less. The all come from China, anyway.I have five of these Ender 3 Pro's now, bought two from Comgrow Amazon, came with the glass bed plates. I print almost exclusively PETG at 248c Nozzle and 85C bed temp, (this makes for very good layer welding) and bought the Creality glass plates and the Bed Weld, water based adhesive so the PETG will let go. The higher temp is to insure both a good layer weld and that the cooling will cause the parts to just come of very easy. Once printed they just come off very easy. If I dry the filament I get almost NO stringing. I can't stress how important dry filament is for nice prints.The metal flex plates and the ones that come with the printers magnetic plastic do not work with PETG at all. They are ruined after two prints. Glass is the best with the Layerneer Bed Weld and I have no problems with adhesion and removal. Just have to wait for cooling. The prints come off as if nothing was holding them when it cools.The parts in the photo are actually functional parts that we can't get from a supplier.. So, naturally I made a CAD drawing and made them. The trick with functional parts is to make the plastic about 1/3 thicker than on injection molded, because of the tiny gaps caused by the space between the "lines" of print. It is not 100% solid even if it looks like it is. And most of my prints use 100% infill because hey are parts getting some heavy use.Overall, it is a good choice and a workhorse printer. For the money it still can't be beaten, That is why the 5 stars. But for those who are “technically challenged”, you may get frustrated with the learning curve. After a few hundred prints you will be a pro. Watch the videos as there are tons of them. There may be equally good or better printers for the price, but the availability of parts, upgrade parts and help resources for these printers is amazing.