Bent,
FWIW, many MX-500 owners also own an OFA or RS just because their MX-500 can be useless without a remote, whether original or "universal" to teach it the discrete commands than many want for their macros, etc. There are some outfits that sell an MX-500, 8811,and JP-1 cable as a package deal. The 8811 can do 15 step macros. I'n not sure whether an extender will increase that or not, I don't mess with macros, or things like favorite channels and the like. Maybe my meomory isn't so poor that I can't remember what those are. Personally, I can't see the draw for an MX-500; it's so "dumb" that it has to be "taught" every little thing. My 1994 will do everything I want it to and a lot more.
Let me know if you'd like to join our little beta group. the more evaluators, the better. You won't lose anything since with JP-1 you'll get what you personally want/need, but it may help others in a situation like you without JP-1 down the road. With a successful beta test, UEIC will have a working new device code that will hopefully work ANY panny tv, and all the others will become obsolete. This would become available for a lot of current remote models, and probably a standard feature for future models.
Jim