I have had both x36 scanners and I bought a sds100 hoping that was going to be my answer to my simulcast problem. I tried all the firmware updates and different antennas every possible thing I could. I have many antennas from stubbys to rs800 to yagis it is definitely got a nice display, and I love the programming ease of sentinel. I needed a radio to keep in my shirt pocket. But the heat coming off the sds100 was unbearable to carry like that. I have sold all my unidens and whistler, and going to sell all my antennas. I bought a g4 and it needs nothing extra, no heat, long antenna or recharge after 5 hours. I hope uniden gets the firmware to work eventually because I was hoping to be able to scan multiple systems on one unit, but until then I value clear comms over all else. So long everyone, I will be around if I can help anyone, as I know all the ins and outs of all the unidens.