Performance hit when brush>Outline>Spacing set too low.

I'm noticing a pattern when using paths and my Outline>Brush Spacing is set below the default %25 percent. Once I go below this number I start to see a serious performance lag in the interface in general and the timeline skipping frames. This only seems to happen in the portion of the timeline where the spacing is set to a low percentage. The rest of the timeline plays fine in front of or after the offending section.

Does anyone have any tips to improove performance. e.g. setting to avoid? thanks-=B