You can't be serious. Reddit is horrible to get around and horrible to read. It looks like a mass of disorganized text. Slashdot is far easier to understand how the flow of comments go and what is a new story and what isn't.
I can't find anything on Reddit.
Reddit was, is, and looks like it always will be, a mess. Even when Slashdot first put in the Javascript in place you could at least still find things on the site.
They still have that, so not so much of a fad. It works but at the time it got in the way for me too and probably contributed to me jumping ship as well.
HN crowd on /. comment moderation with slimmer graphics and collapsible comment trees (like reddit) would probably be close to what I think of as ideal.
Slashdot's moderation UI is pretty much the only thing besides comment-nesting that survived the redesign of X years ago, which ruined the site for me and took me from reading most of my tech commentary there down to a handful per month. Good for them and their UI designers, but I'm still bitter. It really is a terrible site to use.
What did it for me was the much higher volume of stories on reddit. So much of the time, I just didn't care about the Slashdot front page. This is still true on reddit, but at least with more stories there's a better chance of a decent hit rate.
That said, even reddit is getting less interesting these days.
Also, reading at +5 meant, at the time, that I mostly got highly-rated replies to questions or points I didn't see, which meant I then had to do a lot of clicking just to understand what was being said. Combine that with the constant clicking to get more comments or get rid of "helpful" bars that hang out in the middle of the screen, and I gave up, and would have even if I'd had no where else to go.