I am currently having a problem with my Clarity (Boltwood). It is occasionally hanging completely killing the Clarity application (to the point of requiring a system reboot). This has not become an ACP problem because BoltwoodFile adds a layer of protection. By not directly calling into the hung app I am likely preventing ACP from itself hanging. Instead BoltwoodFile detects that the weather information is stale. ACP is then able to cleanly shut the system down.
BTW Bob and I worked on the direct Clarity interface all last summer and eventually diagnosed it causing major ACP problems. I see recently someone got tripped up by using it. If you need more arguments why BoltwoodFile is the safer choice you are welcome to view my threads from 2015