From what I understand, you can use Spriter with a lot more than just C2
But I am not sure how Spriter fits in to this topic because - as of now - you can not draw with Spriter so it can not be lumped in the same category as 'Vector Software'
As for 'game' animation, I would take Spriter over Anime Studio any day... Other animation, it would be the opposite...
Whether the topic is Vector Software, Animation Software or anything else, it is best to compare apples to apples IMHO