I did a bit of snooping this morning. What I found was Davenport (38201), Bettendorf (38238), and Rock Island (38225) to fully encrypted talkgroups.
Seems all low signal sites such as Scott/Muscatine, DeWitt, and any of the SARA sites are not very good here on the week days. Scott/Muscatine however, went all weekend for me without a single error. I am far enough north where simulcast is not a factor. But after around 7 am those low signal sites drop out a lot.