GRBL vs Marlin

I just bought a UNO board and CNC shield for fun. I am wonder what benefits moving GRBL would give me?

I know that it already has support for PWM with out having to remap pins. It would also allow me to shade 3d reliefs with the use of PEP5 (which i own). Would allow spindle control when I switch to a spindle.

Are there perhaps other speed benefits or anything like that since it is a CNC based solution? I have had to switch to using my SD card for wood burning as repetier host cannot process fast enough.

I’m curious about this too… I’m planning on using a Smoothie clone so that I can go with either GRBL or RepRap-alike GCode, but I could be convinced to use my old RAMPS board for this project if the movement is genuinely better.

If you use GRBL with an uno can you run a display and execute gcode from an sd card? I see all these other machine using GRBL but I think I would miss having an SD slot.

since you need something to send the gcode to grbl only solution I could think of would be to use a pi and a usb thumb drive to send to the uno. then you should be able to use displays and setup things the way you want and not have a monitor installed to operate if setup correctly I was pondering doing something like that one day but my machine doesn’t take a break long enough for me to tinker with it more. so I am building another with ramps. GRBL has its limitation its probably not impossible but having something sending the code vs ramps that can read it and output the code. I have had no issues with GRBL and will probably stick with it as much as possible ramps will just be for my laser setup.