I have two issues with appendix carry - although from a draw POV it is a most attractive proposition.
First - a perceived discomfort/inconvenience re sitting ... that I admit is not confirmed thru experience yet. Plus too I can see this only applying to very short barrel guns .... and I like to be 'large'n'heavy' about 3.30 OWB.
Second is the concealment aspect - I use cover almost any time of year which one way or another has enough length down the side to do a good job but - I rarely button anything up and so could see too much opening causing unwanted display.
I guess another factor which is just personal is, I am spoiled with my carry environment and options and so have little need to find anything beyond what already works.
