I installed Duncan's SDI cables with the board in my 596 and it was easy and quick. I use a DVDO iScan HD+ and it works wonderfully with the modified 596. The picture improvement with SDI is superb.

Main system: Cable, Apple TV, HD621, G68D, AC11, 218, DSP7200SE (L+R), DSP3200 (L+R Rear)
2nd system: Cable, Apple TV, MC200, HD621, 568.2, M3100 (L+R)