I’ve not pushed the limits yet, and I tend to be pretty conservative with speed settings. For example, on my Cartesian Ender5, I tend to max out around 80 mm/sec, and those slicer profiles were my starting point on the V4. That said, last night, I was printing a license plate frame, so it had some pretty long stretches. Klipper was showing that I maxed out around 95 mm/sec (with the slicer profile kicked up to 100 mm/sec). Klipper was also estimating that I’d be able to get up to 150 mm/sec reliably.
That print was using a Hemera extruder printing PETG from a 0.4mm nozzle at a .28mm layer height.
I’ve got one final issue to solve on my V4, and then I’m going to try pushing the speed. I’m thinking a XYZ calibration cube scaled up to 200 mm^3 with 0 infill and no top layers. I figure I’ll set the slicer to 150mm/sec, and then keep pushing the speed up manually during the print. I’m hoping to be doing that this weekend.