you cvan only record 40 hours on the normal sky+ box
you can record 80 hours on the skyHD box in SD
but only 20 hours worth of HD programs

if i replace the sky+ box with the skyHD box upstairs theni gain the extra 40 hours worth of recording ability PLUS i get to record the sounds as well and not static

sorry for any confusion

the sky+ system has 2 inputs so you can record 2 seperate programs, but you can still watch a 3rd recorded program

as for the extra bits of hard drive, it's for the sky anytime fuctionality