Vou colar aqui só o primeiro parágrafo do primeiro post:
"First off, a definition: A helper class is a class filled with static methods. It is usually used to isolate a "useful" algorithm. I've seen them in nearly every bit of code I've reviewed. For the record, I consider the use of helper classes to be an antipattern. In other words, an extraordinarily bad idea that should be avoided most of the time."