My DVR Expander- Western Digital

[Tivoman44]

Hello all,
I was wondering if anyone owned this, whether you have Tivo or a regular Dish/DirectTV/Cable DVR.  I want to see if this is worth it, if their are any recurring technical problems from people that would say "do not buy it!"  It sounds pretty simple of connecting it to the box with a coax and then plug it in, then connect the USB and it allows an additional 60 hours of HD recording.  

Steve