I flashed my firmware to the latest Marlin (1.1.0-RC5) last night and updated my motion parameters exactly as Printbus suggested in this post:
http://3dprintboard.com/showthread.p...ll=1#post41192

The results are quite pleasing. My z-axis is quite snappy now. All axes move and home noticeably faster. In a timed test of a single cable chain link the new settings are about 8% faster with no noticeable difference in print quality.

I'm a little concerned with the increase in jerk particularly. Before now, when ever I tried to print too fast (70-100 mm/s) The nozzle tended to "pull up" previously laid down filament strands while rounding corners. I assume the issue is the pressure of the filament being pulled sideways before it had adequate time to cool. With a higher jerk and faster acceleration I wonder if we will actually see a reduction in the maximum print speed.

- How fast can we print with default jerk/accel settings.
- For the exact same print, how fast can we print with the faster settings?
- For both experiments, what is the actual time required, and which is ultimately quicker?

We would want to choose a model with some steep corners to exacerbate any potential problem areas.
Should be a fun experiment to try out.