I’ve been really happy with the MK4 kit I built months ago. While I haven’t seen a Bambu in person, I’m pretty satisfied with the print speed and picked up an 0.6 nozzle in case I really want to print something bigger, faster.

I had seriously considered building a Voron Trident, but have no regrets about my decision to go with Prusa. It’s nice having a machine that didn’t require a bunch of tweaking; it was fun to build the kit but now it’s an appliance I don’t have to mess with; it’s almost like my Brother laser. I hit print, it prints*. (Asterisk because I have to clean the bed sometimes, occasionally I make a poor choice slicing and don’t add a support I needed, etc, but these aren’t printer-specific issues).

As far as bed-slinger vs coreXY, even Bambu recently released a new bed slinger, so I suspect the tradeoff is more complex than just “coreXY is better”. The whole “model flings around” just isn’t a problem I’ve seen in practice; maaaaaybe if you’re building exceptionally tall, thin structures that can’t be oriented properly it could matter but realistically most people are going to mostly print relatively small things. Even fast printers are slow; as soon as you use a printer you’ll realize that huge build volumes are absurd because big prints just take soooooooo loooooong even on fast machines. And there’s either upcoming support or existing support for bed-axis input shaping, since the slicer does know the amount of filament it’s extruding and can tell the firmware how much more the bed weighs as the print proceeds.

I don’t think Bambu printers are an unreasonable choice for people, but I think if Prusa is affordable to someone, their products are still a good choice.

If you are looking for an opinion on the MK4, I’ve had one since August.

The printer itself is fantastic, but I have gripes.

The auto bed leveling isn’t perfect, it tried to destroy my print bed at least once. But with new firmware it hasn’t happened since.

The swappable nozzles are great but way too fiddly to remove. Love how clean the process is though.

GUI and interface as a little slow. Wished they gave it more power, or less to draw.

Bed leveling can leave drops of filament on the bed.

But all of this is just gripes. I have very happy with my purchase and would buy another if the need arises.

I would personally never buy a Bambu printer due to their closed source products and questionable cloud software design decisions. Plus the AMS is just irresponsibly stupid with the amount of filament waste it generates. Printing in multiple materials for pragmatic purposes is one thing… Assemblies with two types of plastic, dissolvable supports, that kind of stuff. But if you need your model to be multicolored, just friggin’ paint it without spending more material on waste than made it into the model.

And if you don’t want to overpay for a Prusa, check out the current gen 3 Qidi machines. I know I keep harping on them and I have no affiliation other than owning two myself (that I bought with my own money) but it has Bambu-like CoreXY performance at a fraction of the cost and the firmware is technically open source, running a modified version of Klipper.

The X-Plus 3 is comparable in raw performance with the Bambu P1S (minus the AMS capability) but is just shy of $100 cheaper, and has a build volume a couple of millimeters larger.

I mulled between the X1c and the MK4.

I have an X1C, but the hardware is the same as the P1S minus the Hardened Extruder/Nozzle which can be upgrade on the P1S. The only thing different is the Bed temp is limited to 110 and no LIDAR.

The X1C is a click and go machine requiring little to no user meddling as far as bed leveling goes. Profiles built-in are OK and you can get community tuned profiles for many different filaments that work even better.

The AMS was the winning factor for me. The purge/pooping can be tuned to produce as little waste as possible. That is the nature of the AMS on Bambu, this is no different then the MMU on the Prusa. The AMS can act as drybox. The downsides of the AMS being you can’t really run non-bambu abrasives and TPU. Certain spools don’t fit in the stock AMS tray, but there is a printed mod called the Hydra Pro that lets you fit bigger spools.

Obviously, the closed vs open source debate is a matter of preference, and if you don’t care about that this is a not really concern or a point to mention. I wish I researched this matter more carefully before I bought it and tried to connect it to Octoprint (no usb port). Also there is no Ethernet, only 2.4 ghz wifi. X1E has Ethernet, but that thing is a scam for businesses and schools requiring Ethernet.

You can run the Bambu in LAN mode which means no cloud is involved at all and you can send your print jobs to the printer from the slicer. The only downsides is losing mobile app access, and you MUST connect the device to the cloud to get firmware update, which you can bring back to LAN mode afterwards.

The bambu is a much faster printer even on the stock hotend, you can upgrade to a CHT clone hotend or the E3D nozzle to push even further flow rates. The hardware is fully capable of running at about 35-ish mm^3 before the 45W heater can’t keep up.

The biggest complaint about the printer was how loud the stepper motors were and now that P1 series get the active motor noise cancelling, it is very silent. The fan noises are the same since you need more cooling when going faster. I print ASA/PETG/PC on this printer so they don’t need much cooling at all and runs practically silent. You can always print slower on PLA and reduce the fan speeds.

Get the printer for you needs. MK4 would have prob been fine for me too if I didn’t want to wait months for it. I am building Voron Trident to fill my needs for a bigger print bed.

Edit: I forgot to mention the repairability of the printer. CoreXY machines are more complicated then bed-slingers. Most parts are replaceable on the X1/P1 with OK documentation. The XY Gantry is a single piece. The front idlers are PERMANENTLY glued. Repairing the printer is a more of a hassle on the Bambu due to how it is was constructed. I think Prusa wins in this category.

My Mk4 is great. Orders of magnitude better than my Mk3. I hate lazily stolen or copied tech. I also hate always online devices. And I do not trust China or Chinese companies with literally any data. So supporting Prusa is a very easy decision for me.

The biggest difference between the two is CoreXY vs CoreXZ. CoreXZ printers like Prusa MK4 are useless in my opinion. Constant bed side to side movement causes your model to vibrate and this vibration amplitude increases with every layer. That means you either have to print everything very slowly or limit yourself to very short models. You’re also missing out on cooling performance.

If you’re looking for an actual upgrade, I’d recommend looking away from bed slingers. Please note that I’m not saying that you should buy any Bambu products, just don’t buy bed slingers.