I've been using WinPatrol for a long time, the only trouble I ever had with it was when it first came with a start-up delayer, the delayer corrupted two of the programs I put in delay. Bill P. quickly fixed it, much like the ALWIL team & the SAS developers do.
avast!, SAS & WinPatrol are great softwares.
When I first installed WinPatrol I notice a big drop in the number of spyware on my computers. Now in addition to WP, I use Spyware Terminator. Now SAS Free & AVG AS can't find any spyware on my computers.
During the past Christmas to New Years holidays ST wasn't updated for 11 or 12 days, but scans with SAS Free were clean, so I think the spyware detections in avast! played an important role in keeping me spyware free.
We all know avast! & SAS were regularly updated during that period.