Simply, it works. Been installing HSB2s for clients on G grade routers for years, so they can have their martinis on the patio and still get online with their laptops. Others may have seen problems with these units, Ive had mine for years and never had...
Had the predecessor, an HSB1. its been an amp for a netgear G grade WAP for years, and Ive seen boosts of double signal strength when measured on a Windows signal strength meter
Huge power supply, but thats not really an issue