For what it is worth, I can tell you that 70' works very well...Running from the MSC-400 into a 6' 3.5mm cable coupled with a second 6' 3.5mm cable into the recommended wall jack. Using about 60' of Cat 6 through the attic and down the wall to the other wall jack. From the wall jack into a URC emitter.

Only surprise was that the JVC HD-ILA rear projection TV doesn't have a remote sensor on the case. The remote sensor is actually on the inside of the unit and picks up IR remote through the front screen. Took the back of TV off and mounted the emitter near the sensor. Works like a champ.