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.

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.

I’d go with the P1S. What are you really getting from the Prusa for $1200? A bed slinger with old stepper drivers that just barely got an upgrade from their old 8-bit control boards. Prusa made sense 4-5 years ago, but at their current price point, they’re getting beat in features by printers half their price. The P1S CoreXY construction is a major improvement for print speed and quality and its ready to go for AMS if you decide you want it at some point.

I do support the open source and customer service of Prusa, and Printables is my preferred site to find STLs, but at the end of the day their printers are just too damned expensive for what they are and I suspect Prusa is going to have a major wakeup call within the next couple years. Previously, they’d only been competing against stripped down Chinese copycats but now they have some serious competition that makes them nearly irrelevant.

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.