Talking, chewing gum, and even just leaning my head back is enough to make the things fall out.
I really wanted to like these things as I have terrible hearing, and the assistive hearing on these is already pretty nice, but they don't do me any good if they won't stay in my ears.
I haven't had this issue with any other earbud I've ever owned.
Do yourself a favor and try a pair out first before you buy, if you can.
EDIT: I am very open to specific recommendations on 3rd-party eartips for these things.