I can reproduce with Java 7. Maven's pick on overloaded methods seems to depend on the sequence of reflected methods -- which has changed in Java 7.

I've chosen BigDecimal because of earlier discussions where it was requested that the given precision should be also used in error message with proper rounding.

As you proposed we can go for the String methods only. Currently the only use cases get their configurations from text files (build.xml, pom.xml). I'll remove BigDecimal methods from the API.