Might be a little late, but the H type doesn't offer battery backup whereas the S series from APC does.
This may make a difference if you have a HTPC and want time for safe shutdown during power outages, or if you don't want to miss a recording due to a power outage.
Also, if you have a projector you may need the battery backup during a power outage so that the fan in the projector will continue to run and cool off the bulb as you shut down the projector.