I actually quit using stumbleupon but I had heard that it wasn't getting updates that frequently and that their growth rate has been slowing down a lot. Doing a quick search I didn't see anyone stating bad things about it, so I don't have anything to point to but I recall hearing it discussed.

if you're not getting new information from HN, Reddit, etc where do you get your daily hit of techi? My route is to check the following:

1.)HN

2.)Delicious top links

3.)Reddit