I don't know about your machine, but on mine (8 core high end rig) it repaints horizontally in rows of 20 pixels, veeeery slowly. The end result is fine, but it definitely freaks out for a solid 3 minutes.
With the `simple` algorithm (arguably better, at least I can read the lines more easily then), 200 labels, and `rounds/tick` set to `100` or so it completes in just a few seconds on my laptop.
