The same is true for Planewalkers that transform into creatures like Gideon Jura ! They're affected by summoning sickness because you cast them in your main phase and not in "the beginning of your most recent turn".
That's true, but I don't see anybody in the thread asking about planeswalkers.
The original question has been answered, thread locked.
I'm pretty sure that whatever rules question may have been asked here has been answered by now. The majority of the discussion in this thread is off topic for the Rulings forum, but since the thread was kind of derailed by the original poster already, I'll refrain from issuing any spam infractions. Thread locked.