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.
Sorry it did not work for you.
I think there may be more than one factor in play as to why the SDS100 works well for some users, but fails at some others. It does seem that the SDS100 is less resistant to interference from adjacent frequencies than older Uniden scanners. A city to my south, Waxahachie, uses conventional 800KHz frequencies for PD & Fire. On one of their frequencies, on my SDS100, I could hear what sounded like a control channel in the background on the audio. That is not present on my 436HP or 536HP, and my HP-1 & HP-2, among other units.
For more experienced users, I think programming is unlikely as a cause. This was not your first rodeo. That could be the case with some of the new users, but there have been several instances of where long time scanner users had issues getting their SDS100 to perform.
The other thing that seems, at least to me, to be a possible factor in lack of success is random manufacturing defects. We knew, based on posts from UPMan, that the initial units shipped would be 'pilot production' scanners. In other words, the first ones the plant had built. There was one user in NJ (RadioDitch, I believe), that was not having success. He then, on a hunch, checked his unit further and found a poor connection between the antenna and the pc board, which he fixed. After that, the scanner worked well, apparently. There have been several other instances where someone has reported poor results, but after they exchanged their radio with their dealer, the replacement worked much better.
A number of years ago, I worked as a tech at several new car dealerships. Every time a new model, or a completely redesigned version of an existing vehicle, came out, the first units often had 'teething troubles'; poor door and window fit, rattles & wind noises, and other issues, until the production plant hit their stride & learned how to build the new units in a consistent manner. Whether something similar is happening with the initial shipments of the SDS100 is at least a potential cause of inconsistent results.