Does the 616Flex program the same as the 616ex or the 816GK ?

I am almost positive they do. There might be one or two programs that are different.

Thats what i thought, thanks RCA

the 616 flex's software seems to give better text "hints" in the LCD when you are programming---also the 16 station buttons can be programmed for other features, & one touch speed dials --whild, i believe, the ex can only support the stations on those keys.
Otherwise...i have found the programming to be the same.