Haven't watched U.S. House of Cards yet, but from my perspective (or hope?) it's getting a lot of the same kind of opinion that Boss did, only with far far more attention. You bought in with Grammer as Kane and then bought into the entire series from there or just couldn't get involved.
I agree that it's a good point of comparison. House of Cards compares favorably, however, because the script writing and secondary characters don't detract from Spacey's performance. Nearly everything on House of Cards is done with competence, even when it isn't so thrilling.
Overall though, I think the medium in which House of Cards is being delivered is helping smooth over some of its flaws. I don't think the show is compelling to the point where you would make sure to tune in every week. Since it's all available up front, you can afford to be less critical and go along with the ride.