Nifty!  The stitch guide foot has really helped me keep my stitches straighter.  Because the guide floats just above the moving fabric, it is always clearly in view, unlike the markings on the throat plate.  I did make one 'hack', which was to use different colored sharpie markers to emphasize three width marks I use most commonly.  This way I don't need to count out which mark I need constantly, merely remember I want the red one, for example; and glare on the shiny metal is less of an issue. This addition has made it a breeze to stay on track with the proper seam allowance.  The markings are on top of the guide, while the fabric moves under it, so I don't worry about the marks rubbing off on the fabric, but I also let them dry a full day before even trying it out.  The foot itself is very well made, very sturdy, and the guide does not interfere with the fabric at all, it hovers just above it, and the marked guide itself is quite substantial and I do not believe that it would become bent or twisted with normal use.