I started using Klipper and Fluidd on a Pi with my Ender 3 v2 (motivated by the wrong reasons).
Why should you consider this? 1) speed of printing, 2) ease of tinkering.
To use Klipper, you flash a lightweight firmware for your printer and the printer just does basic, fundamental control. Higher level commands are evaluated on the Pi. It takes some of the processing complexity off the printer controller – which could be significant if you have an 8bit board like an Ender 3 orignial.
Also, higher level config is done on the Pi so chances are you can now tinker away changing hotends, offsets, levelling sensors without having to flash the firmware again.
Fluidd is an alternative to Octopi. You can use Octopi still but I think Fluidd has some advantages for supporting changes to Klipper configuration files. I switched from Octopi to Fluidd because I has comms issues between the Pi and the printer… but it turned out to be noise due to different power supplies. Fluidd can emulate Octopi for integration with things like Cura so you can 'save to Octopi' and the slice goes direct to the Pi ready to print.
An example of interesting speed options is 'input shaping'. You can attach an accelerometer to your printer, measure the resonance response, and then apply active damping to account for that. It allow much faster acceleration without ringing. And acceleration (rather than max print speed) is usually the thing that most impacts print time.
If you just want to print and use the printer as a 'tool' then forget all this and stick with a Prusa, If you want to tinker, then get the cheapest Ender 3 and go this route!
Edited By jaCK Hobson on 15/04/2021 17:46:54