Changing creatures types has always been a favourite trick of mine and I honestly didn't know this card existed until today. I had always thought that I was going to be forced to use Artificial Evolution as my Instant-speed, single target creature type change, but now I know better. The only real problem with changing creature type is that its usefulness is very limited, but it can still be pretty fun. Use with with something like Endemic Plague or a Champion creature for maximum effect.
Pros: Instant-speed cheap creature type change
Cons: Limited usefulness, only until EOT