I use the fork pins 'all of the time'. They are very fine steel so you can "slowly" sew over them. I teach Basic Quilting at a LQS and these fork pins are one of my 'required tools'. Using these pins, my beginning students have perfectly matched seams and perfect points in their very first block.
Yes, they are pricey! However, the results are worth the price. The secret to using these is to insert them into the fabric at an angle, then gently push down on the end of the pin to get the other ends back up through the fabric.
Use the same concept that we have always used---vertical pin through the points or seams to be matched, then stradle the vertical pin with the fork pin. I insert the fork pin(s) on either side of the exact point that I want to stitch, this gives me a guide of the exact place I want the sewing machine needle to enter the fabric to make the points match. Sew slowly over the pins.