Thought I would provide my experiences with my 536 after months. Just want to say that I had a hell of a time getting 536 up to par. Programmed my 996 several times and had it down pretty well but still had problems with this one. My reception sucked on the 536 compared to 996. My antenna has always been straight up on 996 and struggling to get reception on 536 until putting the antenna at about 4:30 (looking at angle as clock). Reception fixed after a little over a month. Couldn't believe it when I got it. Reception is now GREAT!! Am getting P25 signals at around 4 bars and getting the analog very close to 996. After setting the threshold settings error stays under 10. By the way only have control frequency of multiple sites set up as one site. Currently using the unsupported firmware that 536's shipped with. Only problem I get with that firmware is the discovery holds on control channels at times. Overall I can say that I am now pleased with my 536. I worked on it everyday for over a month until one day putting the antenna at a down angle which makes no sense to me. Now just waiting for analyze and app features and will feel as though I got my $$ worth. Upman if you read this is there a chance we will see a beta for the 536? Also has there been anymore progress on the siren app deal? Understand it is hard to give dates because you can't predict future but another update would be nice. At least keeps us all with some faith and some hope. Want to also thank everyone for all their efforts in helping everyone here. Without you all these forums would die.