Quoted By:
Speed is important no matter what. Especially with the power creep and Nidoking's lacking defenses. Going first always means you get at least one attack in.
If you go second, it usually doesn't matter, especially if you're a sweeper. If you don't get a hit in, you're dead.
Just look at why Close Combat basically has no drawbacks. Why so many great Pokemon are just attack/speed variants with like 60 base defenses.
They all have enough power to kill you before you can even touch them.