I prefer a flap heel, but
-No measuring, just knit until your flap is a square.
-Turning is a breeze
-You don't have to place markers where you wrap and turn the heel.
-Can sometimes take longer to work.
-You have to pick up stitches, which some find difficult.
-Sometimes to keep the decreases even.
-Doesn't take as long to work.
-You can work it in any stitch you chose.
-You have to place markers where you turn the rows.
-Can sometimes be harder to see in a dark yarn.
Hope that helps!