I had an interesting moment with the TF10s. The couple other IEMs I have all use the medium sized tips and they work for me. I have two different sized ear holes, the right side fitting my pointer finger in, and the left side being more pinky finger sized, but I still can manage to use the same size tips. So, I started out using the medium tips that are already on the TF10 and everything is decent. Then I tried the included Comply tips and prefer the comfort of those over the stock tips. Bass was better, but overall the sound was a bit muffled. I've swapped back and forth a few times.
I laughed pretty good when someone called them the Comply mufflers, because it was true.
After a night with my Senn HD 600s I had to change something because the muffling was just too much.
I tried the small tips but that didn't work. Back to the mediums. Then the Comply tips, but the muffling was there again. Heck, why not, I'll try the big ones. Jam them in my ears and BOOM! Fat, full bass, and no muffling or recessed midrange. When I pull the left one out, the tip flips inside out it's in there so tight. Comfort has not been an issue, but maybe my ears have gained some toughness and can take it, but really, this isn't uncomfortable.
Just wanted to share because this experiment has opened the door for me.