Probably pretty close to a blind stitch.

I finally had a chance to try the unironed binding. I did a small preemie quilt and ironed half the binding and left the other half not ironed. Other than I found doing the mitre a bit tricky with the unironed section, I really didn’t find the machine stitching part difficult. When I started the hand sewing I don’t see any difference. This was a fun experiment and I found all the comments and info quite interesting. Going forward I probably won’t iron my binding anymore. I think the mitre will get easier with practice and ironing is not my favourite activity.

I don't press the binding. What I do is use Elmers Washable School Glue. Just a few dots along the edge, fold, and just press the edge so the glue dries. Then glue it to the quilt instead of using pins or clips. Keep the glue inside the seam allowance and sew it on just like any binding.