Almost the same here, I like Slashdot as much as HN for the content they bring to me and yes, the maturity (something very important on the web).

However, i can't get myself around their interface, i don't understand it/don't like it, i feel like their lacking a designer or something... in comparison with HN.

So, I spend less time on it, and didn't create an account or anything, eventhough i'd like to...their UI just doesn't feel right.