My Bernina came with a 1/4" foot with a guide, and I didn't like it, so I removed the guide. The reason I don't like it, is because when I match points, I use a pin, and sew right up to the pin. But the guide catches on the pin and gives the fabric a little tweak, and I get a crooked seam.
What I tell my beginning piecing students it that everyone finds their scant 1/4" seam differently. I find mine by adjusting the needle bar to the right one notch, and guiding the fabric edge just inside the feed dog hole. That would be guiding it from the bottom. Some find it by guiding the fabric edge along the edge of their 1/4" presser foot. That would be guiding it from the top. A good way to find your scant 1/4" seam is to sew on 1/4" graph paper, and see where you need to guide the edge of the fabric to get your needle just to the right of the line.