I've exclusivly used the whisper filters on my FW
tanks for many many years without a single problem. I just read that article and it seems that he's based every sectin of the review on one fault he experienced.
I had a whisper that I had used on a FW
tank that had a sand substrate and had a pleco that loved tostir up the sand resulting a lot of sand getting cought up in the impeller. The sand reeked havoc on the impeller but I never had a single problem with it even though it was heavily damaged by the sand.