I like to score my boules and have used a single edged razor blade in the past. They kept disappearing as my DH uses them for various things around the farm. I decided to buy a REAL lame' for my scoring and found that there is a huge difference. I love my new lame"! It makes much deeper cuts than the razor blade did and it is nice to have something with a handle. It came with a package of blades which will most likely last quite awhile. FYI, I bought it through Breadtopia.
I also just bought the lame from Breadtopia and am finding the same thing as you. I am seeing much better scoring since I switched from a small serrated paring knife to the lame. Such a good device and so cheap as well. Very good value there.
I just made the Tartine Country Bread using your flours and the result was fantastic. I wish I had a camera because the loaves came out looking very much like Chad's in his book. Fantastic taste. Only difference is that I mixed the flours a wee bit differently and I used about 25 grams less water than Chad did in his recipe. Win all the way and the scoring even came out just the way I wanted it to.