I have a couple tubes of Geocell, too. I like that product. But this is a much harder caulk than that. It does leave a nail imprint if one pushes hard. I haven't had the chance to call FR yet. I hope to have time tomorrow, well that would be today actually, as I am just getting time to reply.
I am a bit of a night owl.
As I stated above, it is used in certain areas on my roof. Mainly in the corners along the bend as it curves down.
I'll report back once I hear from FR on which product this is.