Just back from 5 days at the parks. As someone that hasn't been in a standby line of over 20 minutes in years, the experience was new and someone annoying. Although most waits were tolerable, and I did get to see a few standby queues I had never seen before, I cannot wait for the FP+ system to return.
Longest waits (all weekdays) were Micky and Minney's Runaway Railway, 50 minutes; Splash Mountain 40 minutes; Kilimajaro Safari, 40 minutes; Slinky Dog Dash 45 minutes.
I concur that posted wait times are inflated, usually about twice the actual wait time. Lines are shorter in the morning and can get really long in the mid-afternoon. They can be pretty short near close as well.
Remember, all of these times were on weekdays last week.