My testing on a multicoupler vs. my best analog scanners tells me that sensitivity isn't the problem. The problems on VHF and UHF for me seem to involve interference / images / intermod, as well as a high level of white noise when listening to analog frequencies. If the signals are stronger these problems are sometimes lessened, but the issues remain, popping up here and there. The weird part is that I can sometimes get my SDS200 to receive weak VHF fireground signals and ham 2 meter simplex signals from miles away, matching closely what my best scanners can do....they even drop off at similar moments squelching from lack of signal. So the SDS200 hears the signal almost as well as the other scanners, but even if there is no intermod or interference, there is always an excessively high white noise level, making the same received signal much less enjoyable to listen to on the SDS200.
Overall, VHF / UHF analog are still good enough that I can avoid weaker stations but still enjoy having my old analog stuff in the scan rotation along with the the simulcast systems that the SDS scanners specialize in. I really appreciate having the ability to do that. For the most part that is "the dream" I've had for a quite a while. Still, for weak signal VHF and UHF analog work, the SDS scanners are just not the best choice. BCT15X's are dirt cheap, you can afford to buy a rack of them for the price of an SDS200.