Great module! Has saved me a lot of time and stress in parsing MIB files myself.
However, the interface to call the loading is not particularly nice (3 parameter reply? $error appears to be set even if there are no errors), and some of the documentation doesn't seem to match (using -StandardMIBs as the key to mib_load does not seem to work, but dropping the hyphen does).
There are no tests to the module either.
I've added a patch to rt which includes the start of some tests, which I hope the author takes on. I've given this module 4 stars, even though all the individual ratings are 3 or below, just because it has saved me a lot of time and effort.