The 6150 series keypads have always been the non-programming version of the 6160s. Mimicking many of the features, the 6160s allow users many of the same functions the 6160s have minus the simple programming. They are usually used as a companion keypad, for that reason. The 6160 used to program, the 6150 used as the peripheral keypads.
The 6150V, the voice annunciating version of the 6150 has been discontinued. For those who are after a voice annunciation option, the 6160V is the replacement that will work on a VISTA wired security system.