I have bought numerous HIS products, with only one RMA, which was handled without issues according to their standard RMA procedure.
I like their coolers. Other than my own personal experiences with the brand (6-7 cards, a statistically insignificant sample), my overall impression of the brand remains mixed. I see a lot of citations for poor build quality on some cards, and it seems perhaps they have two "levels" of product. One is a cut-down budget model intended to meet a price point, and the other is everything else. I'd buy another of their cards myself, but I'd make sure it isn't that base model.