It can work, but I think it's harder to scale to something the size of HN without losing some of the important properties HN has.
For example, I think it's useful that on balance the top few comments and their discussion are likely to be interesting, and the last few comments are unlikely to be interesting.
For example, I think it's useful that on balance the top few comments and their discussion are likely to be interesting, and the last few comments are unlikely to be interesting.