Akira in both Anime and Manga are masterpieces. But there's a split between the two Verisons. This is all opinion based. I give you the comparison.
This might be bias to say the manga is better, but the anime film was just a summary of the six volumes contain 2,000 pages. However, the favor depends the person. There is major differences.
The anime for manga reader may find things different and hate it because the magma contained better information and better narrative. Not always the case, long stories tend to be vey complex and requires figuring out what's going on. The themes are presented in the both version, but what's the main focus of it.
If it was OVA or anime series, it could been a great series. There is a major problem about it. The production cost was major issue for anime companies in the 80s like Urusei Yatsura.
The creator of the Manga somehow knew making Akira a series with the Anine format will take too long and too costly. That's he settled for script that we have the current version of the anime. That explains why the Manga was half- done when it was released.
Akira- Anime or Manga:
This is very tough to say. Akira is very interesting character. In the manga, he is alive and poses a great threat and at the anime, he's dead. This where the split is that I would use example like Nostalgia Critic's old vs. New Lord of the Rings. To me, the anime has give Akira more mystery and by saying his name had tranced the frantics. In the manga, they worship a kid and kinda silly.
I think not showing Akira is more effective as a symbolism that what is God as in the anime what is Akira. In the manga, it's just some kid that everyone wants to use. The big question is that in the manga, why they keep him alive all this time?
In the anime, he's dead besides at the time they killed him and use samples from him to collect data and stored his remains. Despite his death, he given a aura of fear and awe. I'm not saying that Manga Akira is bad, he still poses a threat.
The main problem is that Manga Akira is that he's a boring character to begin with. Anime one was more effective that questions you what is Akira rather to show him and use him as a plot device. I give the Anime Akira this round.
This is no brainier. The anime has remove or downplayed major characters of the Manga. But even downplayed characters do have appearance regardless are badass. But the personalities are different.
The colonel was acting like a James Bond villain until a hero in the last three volumes. In the Anime, he's given more reasonable rational character who knows the risks. I think anime colonel was much stronger than the manga.
Kanada and Tetsuo are somewhat flowed naturally in both versions. But that depends if you prefer the manga or the Anime. But anime Tetsuo was too rushed and Manga Tetsuo had more time to expand his character.
The characters are different in ways to say. But the manga has better and more interesting characters than the anime. I give points to the Manga.
The manga's ending was stupid. Hear me out, why in the hell that Kanada and his friends form Great Tokyo Empire to begin with? There's no rhythm or reason to start a nation with no resources, no government, no financial power, and their army is super weak.
I mean the UN and US gets driven away from punks? That's stupid. They have enough firepower to wipe out a micro nation, but they are stopped by a bunch of punks pretending to be nation? YOU can't be serious! I mean UN will not recognize a micro nation just because they declared themselves an nation.
The magma ending was just plain stupid and the anime ending was much better. The anime ending was better than having that nonsense to begin with. The anime ending will left the viewer to think how they will rebuild themselves.
The anime ending wins this one.
I think both verisons are great on their own. The anime is a masterpiece made animated and film revolution. The manga was it's own masterpiece with good storyline and characters. So, I suggest get both of them to enjoy the an art masterpiece.