David Alan Abramczyk said:
It's what I think they call Adaptation Decay.
Akane appeared more violent in the anime, due to the writers collapsing storylines together. Most people who fan-write for Ranma 1/2 have only seen the anime, and then they exaggerate her temper issues, to make her some sort of beserker with a hair trigger.
Groans... another Akane thread...
Personally, I can't truly say I like or hate Akane, but I do not like her in a relationship with Ranma. Even stating that is a bit much, as she has quite the number of character flaws I do dislike.
I will say any story I read that is an Akane/Ranma match the author must work to make me believe that relationship is believable. As I just do not see a lasting one between them working with canon personalities and history intact. I do not believe they have enough trust for each other, and as such friendship and love between them is IMHO near impossible.
Akane is nice to everyone in the series except Ranma, Happosai, the orning hentai squad, and Kuno. The last three I state basically get everything they deserve. But when treating even your kidnappers better than your supposed fiancee, or that fiancee's rival better...
She makes you have to work to like her.
Ranma is no innocent in the relationship problems, unlike tons of fannon based stories may imply. He causes a lot of issues, so it is not just on Akane's head they are where they are.
As for manga vs. anime. I have to say, having seen both, I honestly do not get where everyone states she is so much nicer to him in manga. I just am not seeing it. I will agree she is *slightly* nicer, but that really is not saying too much.
EDIT: edited multiple times for clarity.