I called Escort this morning because my mother's 8500, Rev 13 has been acting up. It has been intermittently showing "Service Required" and random full Ka blasts that don't stop till it is turned off. When I asked about a buyback for a newer model, the fellow told me that they would give $50 toward an x50. I asked if it was worth it, he told me that if it were him, he would have this unit repaired, that the antenna tuning was a miniscule difference and the POP is not really necessary. I am pretty certain that we don't have POP in Houston, (I have it turned off on my V1) so that is cool with me, but how much better than the regular 8500 is the x50? Is it worth an upgrade to a new unit? I bought my wife an x50 last year, but I have not spent a lot of time with it. Please let me know. Thanks!