Hi,
In most cases the specs are very similar. It usually comes down to the corporate standard. i.e. if a customer has IBM servers with IBM serivce contracts or spares for the hardware etc.
Could also come down to network management as well. Does the customer use IBM director, or HP sys insight manager already?
Last install I did notice that in the 7825 platform, the HP version had the drive accessible without pulling the server out of the rack. On the IBM you had to pull the server out. I doubt this applies now.
Cheers,
Tim.