I’ve got a Janome 8900 and am very happy with the blind hem foot, it makes hemming a breeze.
It seems counter intuitive that you stitch inside the hem but it so easy.
I usually overlock the raw edge and then press up the hem. Some people tell you to press the edge you are stitching in to but I find it better to just roll the fabric, this keeps the visible stitch much smaller.
I also use the foot for top stitching, the metal edge helps to keep things even.