[f5fstop]

Actually, Directed Electronics Incorporated owns:
Viper
Clifford
Hornet
Sidewinder
Python
Rattler
Valet
Wasp
(and maybe a few more)
And I believe they all offer a responder type system; be it called "Responder" or "Two-Way."
They do this for marketing. This way, three stores in the same block could sell what seems like three diffrerent systems, yet they are almost identical except for the color of the remotes.

I have the Viper, but almost purchased a Clifford.

Only thing I recommend is to keep the screen on the responder alart from getting all scrathed up, put some of that protective film from 3M. I have changed mine twice since it gets scratched.
If anyone wants a template for the Viper reponder alert (and any other) let me know.