In one of the most recent Smogon magazines they discussed in game tiers.
They cite scyther in heart gold and soul silver as a top tier. Right now I am playing through and have a scyther that is at level 21. I am conflicted about whether or not to evolve it. If I evolve it i lose stab on wing attack but gain stab on metal claw. I also get a lot of resistances and higher attack if I evolve but lower speed. What do you think? Thanks Smogon Community!