If I may, I want to share my experience with organ masters. I started playing the Organ in April of this year and I had been playing with socks all the time -- at home and at church in my lessons. I managed okay, although I felt heeling took a bit of an effort due to the lack of shoe heels.
I received my organ masters yesterday to much anticipation. I put them on (fit like a glove) and started playing. I was very impressed from the beginning, I could still feel the pedals through the suede sole and heeling with an actual heel makes it so much easier. They don't look half-bad either.
I played maybe 2 and a half hours yesterday only to notice that wearing shoes is actually pushing me to improve my pedaling technique. Obviously it isn't as easy to press continuous pedals while wearing shoes and neither is gripping the sharps since you can't curl up your toes when moving around the pedalboard so a better feet position has to be achieved. I find that it is pushing me to become better at doing stuff like keeping my knees together so my feet curve outward and actually rotate my body when playing the high and low parts of the pedalboard. The heel is not very grippy which encourages me to actually think ahead and put my feet at the right angle to hit the pedal with the heel right on so that it won't slip.
All in all I'm very happy with my purchase. I got used to them in around half an hour and I'm already seeing improvements in my playing. The two gripes I have with them is that they are indeed hot and the pedals aren't very grippy. I can live with that.