The tuner is quite new and from the reviews I've seen had some problems with the first models, but it sounds like they are fixing those problems. That might be a good tuner but there is very little info about it since it's only a couple of months old.
How are you going to hook up the cable box? I'm guessing your going to use the cable box to tune the channels, then output them to your tuner card. That might be the only workaround for getting encrypted HD channels to work on the tuner card.
Looks good to me though, be the test subject and let us know how it goes.