Speed Test Tower

I wanted to see how fast I could push my printer and still get quality prints. I couldn't find a good speed test tower, so I made one.
Here is the gcode I used in Slic3r PE (goes in printer settings, custom gcode, after layer change) to change speed at the various layers :
;[layer_z]
{if layer_num==5}M220 S120{endif}
{if layer_num==77}M220 S130{endif}
{if layer_num==152}M220 S140{endif}
{if layer_num==227}M220 S150{endif}
{if layer_num==302}M220 S160{endif}

I started with a base pr