It does make it crisper, but as i said before, at the expense of your whites.
Your other option is to apply the filter, and then take out extraneous lines with a white brush or eraser (depending on the blend settings you use)
Also, if you havn't tried this method, give it a bash. It's far more selective in what it darkens and leave white than find edges.
http://www.graphic-design.com/Photoshop ... index.html
<a href="http://i13.tinypic.com/54ohpmo.jpg">Example</a>
here's a quick test of the blur to sketch process i knocked up using one of your pages. From left to right, original, find edges and watercolour style, and then the blur/sketch effect. (Granted it looks a bit grainy because i was using the jpeg source with all the text already on it, and at view for web resolution)
the differences are admittedly subtle, but the sketch style concentrates on making lines out of the darker areas and leaving the whites white. One cup does the whole wash!
Anyway, it's interesting to see your process, and i am majorly impressed with the dedication you've poured into it. You definitely have a unique style i havn't seen around much.