I have seen it and unfortunately, I'm a 5. I quite literally cannot picture an apple in any form. I understand what I'm supposed to be picturing but when I try there's nothing that appears. It's fascinating to me too, since I typically have quite vivid dreams and I've been able to lucid dream on a number of occasions.

Now, I've chatted with friends, and my one friend is close to a 2, or maybe a 1 from how he described it (being able to visualize the apple and rotate it 3-dimensionally).