I'm trying to decide between this unit at Costco http://www.costco.com/Swann-16-Channel-HD-NVR-Security-System-with-3TB-HDD-and-8-3MP-HD-IP-Cameras.product.100144944.html and this one at Sam's http://www.samsclub.com/sams/8ch-1080p-nvr-8x4/prod16050413.ip?navAction
Is one difference being the system from Sam's has audio? I'm really trying to compare the 2 systms, besides the fact that the Costco unit comes with 8 cameras instead of 4. Does anyone know the actual differences between the 2...or suggestions on which one may be better?