If the specifications are the same, I'm assuming that the hard drive is the same size as well. Therefore my advice would be to check what sizes the partitioned drives are!
Reason for bringing that up is most manufacturers evenly divide the hard drives. However, when a friend bought a Toshiba the C:\ Drive was well over 100 GB (can't remember the exact size.) BUT the D:\ drive was only 7 GB. (just a side note, that's the one I mentioned I had to resize in another thread)
If you don't care what size the D:\ drive is, then probably wouldn't matter which one you get. If you are concerned about size and want to use it for storing data etc., then go with HP.
I'd also check to see which one has the better support etc. From my previous experience with HP it has been really good.