I think there's a few adjustments that need to be made for the kind of games the majority of us are playing.
First, I should say I'm talking about the original Super System, not the sequel, and just the hold 'em sections (I haven't actually tried applying the stud / lowball strategies).
In general, I think the limit hold 'em advice holds up pretty well.
I think the biggest problem that you'll face applying the no-limit section, however, is that for the most part it seems to assume you'll be facing weak-tight opponents.
I'm sure that was the predominant style at the time it was written, but it's not any more - you won't always be able to run over the table like the book suggests, because we're likely to be facing a lot more loose players and calling stations, which in turn demand a tighter strategy. And when you play that tighter strategy, you're not in as many pots and therefore not picking up as many small pots.
In the right game I'm sure it can still work wonders, but I don't think we encounter those ideal conditions these days.
The overall message that you should punish weakness in other players and tread carefully when you stand to either win a small pot or lose a big one still rings true though.