Well the first time I remembered seeing Sakura about
three years back, when I first liked Naruto, I couldn't
stand her. I always remembered questioning myself, "How could she yell at Naruto when she wasn't any better herself?" That bothered me for the longest time. I couldn't
stand her. After the episode where she cut her hair off I hopped that my opinion of her would turn around but
obviously, it did not.
The more I got into
Part II, the more I really found Sakura Haruno amazing. She still had that shy part to her but she showed how powerful she was. For instance, between that time with Sasori, she had gotten stabbed in the stomach. She really proved herself and I even believe that Sakura
is stronger than Karin. I pretty much KNOW that she's one of the strongest females so far. She's a great apprentice to Tsunade.
I basically noticed that Sakura was strong around that time when she asked Tsunade to start training her. We already could see that Sakura had
fantastic Chakra control, but she never really did much about it (for instance, the Chrakra climbing episodes). Sakura trained hard and it showed off. OBVIOUSLY.
[ I guess half of this crap should be in a spoiler tag. ]