I'm thinking about getting an LHe card and was wondering if it is able to capture video via HD-SDI while capturing ANALOG audio via XLR. Or, does the system only let you capture analog audio with analog video and digital audio with digital video?
yes, you can capture HD-SDI video AND analog audio at the same time (like analog audio from an analog audio mixer). this is common. This setting is made in the AJA Kona Control Panel, on the INPUT tab.