I've been working a lot on my 8th notes, and with the EE books as well. I've found that as i work with my bowing techniques the sound improves. I was tensing a lot trying to meet the right timing and i think i ended up pressing to hard and had short harsh strokes of my bow. if that makes sense.

I know what i used was fiddlerman's techniques for practicing with the bow quietly (especially the paint brush method) and focusing more on relaxation and the more i relaxed the more the songs started sounding better and were easier to play.  I'm always working on intonation so i know thats a another problem for me but its a work in progress

I'm not sure if this helped you at all but good luck!