sYnaXisProbably the others work for charging at I guess 900 mA when connected to a powered-on computer, wherease the charging port works via the power adapter independent of any connected computer and possibly delivering more amperage as per the USB Battery Charging specification.
sYnaXisI emailed juiced systems about it. The port marked with the charge icon will charge at 2.1 amps. All other ports run at the normal .5-.9 amp. So I guess to answer your question all ports can be used to charge devices but only one port can supply more current if the device asks for it.
I finally just bought a 5 port anker usb charger as that's all I really wanted a usb hub for. Only does 5 devices but it's 5volt/8amp so has plenty of power. Just search amazon for usb charger and it will be like the 3rd result with 2000+ ratings. Make sure to get the PowerIQ one not the older model that had certain ports dedicated to certain things.
I finally just bought a 5 port anker usb charger as that's all I really wanted a usb hub for. Only does 5 devices but it's 5volt/8amp so has plenty of power. Just search amazon for usb charger and it will be like the 3rd result with 2000+ ratings. Make sure to get the PowerIQ one not the older model that had certain ports dedicated to certain things.