when driving around town yes, but when driving on long trips I tend to try to keep my foot and ankle at a relaxed angle by sliding my heel fowards and back when holding steady speeds, but then again I have bad ankles and am used to autocross racing where I use my whole leg and my heel never touches the floor.
The hanging pedal allows for more heel positions. My first 4 cars all had floor hinged gas pedals, so I could really appreciate the difference when I got my first new car with a suspended pedal. If you only drive short trips or do a lot of running etc then it probably won't matter. Being an OF I look for comfort over contortions.

 

I used one from an 89 F-150. I with a little tweaking, it worked perfectly. Mounts to the firewall and has the spacers under it, so that carpet and pad will not interfere with mounting.