This will be our tenth season using them. Never had issues. Most dependable feed service device we utilize and, again, used in the pens where the most deer are attracted to (for whatever reason). We have nine of them on our place with two of those models being the 3,000 pound systems.
At some point, ASF went to troughs instead of tubes. The trough systems appear more likely to get clogged in the unusual circumstance where there is heavy rain.
Big deer just don't seem bothered by them -