During my brief time with an ALIS Fuji screen (same as Hitachi I think) I found that it was poor with a progressive feed and very good with interlaced.

Your 596 is interlaced only I guess so you're probably not impacted.

Whether HDMI (or SDI/DVI for that matter) is any better depends on how well the digital side has been implemented. There are a few dealers/ISF calibration type chaps on the AVforum who have concluded that component into some screens is better than DVI.

SO, Ian's advice to take your unit to a store and test it for real is the only way. If you can't do that practically, then digest the avforum threads for while and see what the average or consensus is there is next best.

Rgds,
Nick