Another Update
It's Wednesday, and I still can't receive calls via the number I was assigned by SunRocket. I'm starting to get a bit disillusioned. A subsequent call to tech support elicited the comment that the activation period for numbers that need to be ported from Choice One (why it's a Choice One number when SunRocket assigned it to me is a mystery) is 7 days from the date the Gizmo is plugged in and not the date I signed up.
So . . . if it's not in service for inbound calling by the end of the day Friday, I think I'll be sending it back. If it takes this long to port a number to which they purportedly have direct access, imagine how long it will take to port one from a landline provider . . .