Ive had no issue with them falling out of my ears, even when running. (it comes with three different sizes)
When they arrive they do sound incredibly flat/dull, you will want to download the app and apply the following EQ to make it sound decent:
60 Hz +8
100 Hz -2
230 Hz -5
500 Hz +2
1100 Hz -2
2400 Hz +8
5400 Hz +1
12000 Hz +11
(these settings wont apply to the buds unless the phone location is turned on when launching the app)