I think the main difference that a lot of people aren't mentioning is that it can u-turn to a trapper pokemon. Then again, that's a lot of why shed shell skarm exists anyhow. Edit: Shouting, you wait until genesect isn't IN to spike. Once you have a layer of spikes and SR, genesect goes down quick and hard. Alternately, lead with sableye and burn his dumbshit ass-12% a turn from then on.