Today I'm reading the main site, normally I would be reading a daily/weekly/monthly digest. Today I'm commenting, any other day I probably wouldn't. I'm still the same person.
People sometimes think it's only useful if you're consuming HN all the time, but it turns out it's just another random slice of HN, one that's guaranteed to be all new no matter how often you check.
...except if I get bored on a Friday and look at new topics, which explains how I saw this link in the first place...
I still have a link to comments for each story in Google Reader (although I don't get the number of comments). What I gain with Reader is the ability to mark all as read and therefore the ability to see what's new since the last time I checked.
"I still have a link to comments for each story in Google Reader (although I don't get the number of comments)"
If you browse comments a lot you end up spending almost all your time outside the reader anyway, so it doesn't seem to help that much. I can see how you want to avoid the frontpage if you check HN often - it just shows you the same stories all the time.
I've thought a lot about this, and RSS doesn't really fit social news, especially comments. So far the best UI I've been able to come up with is hackerstream like I said elsewhere in this thread.
If it seems like the comments might be interesting I just click the 'comments' link.