Looking at the comments, I am shocked how many people are concerned that people will ship things with type errors into production or this would somehow relax the standards of Haskell programs, going to the length to suggest that some short of sabotage should be levied when the flag to enable this is on.

This is a very good, and rather unique feature. I have wished for an equivalent when figuring out some stuff in C programs for long time; I cannot imagine a person who has to maintain and change a large program and cannot understand the huge utility of this device.