hi,
Are you testing this inside the editor? Have you tested it when published? Unity Editor and PlayMaker Editor do impact on performances.
I have created a "Game View Only" Unity layout, where litteraly, I removed all tabs and I am only left with the gameView, then when I press play, this is the closest I can get in terms of performances with minimal editor impact.
Now, what you seem to measure if the performance hit form using iTween which creates and destroys components, and its know as having an impact on perfs. Do you have a lot of things going on in the scene or just that test?
bye,
Jean