Anyone who says that Sasuke is better at Chakra Manipulation than is on something else. Naruto and his Rasengan is the HIGHEST form of Shape Manipulation in the Naruto Universe. Why? Because it is based off one the other powerful techniques that Naruto is able to do, the Bijuu Ball(Which is the ultimate form of both precision and destruction for whomever talked about that).
Sasuke has done two incredible things with lighting and that is making it into a sword(whichother people have been able to do) and use Kirin(whichis not even his jutsu. Yea Orochimaru taught him that). As far as Amaterasu, Sasuke has been working off of instinct and needed to use the Amaterasu to cover his Susanoo because his weapons are not as dangerous as the ones Itachi's Susanoo have. I believe that Itachi was way better than what he was showing with Amaterasu but what was the point when he had the ultimate spiritual weapons and he was also dying.
On the other hand Naruto has learned the highest form of chakra manipulation which only took him 2 weeks to learn. Anything that was impossible to either Jiraiya or Kakashi Naruto figured it out because he is a genius in his own right. It was suppose to be impossible for him to use Rasengan because of his bad chakra control(because of him having to supress Kurama's chakra all the time), yet he figured out how to use it and also use it fast & strategically. Kakashi told him that it was impossible for him to fuse the HIGHEST form of shape manipulation of chakra with his nature type and that it would take someone 20 years to learn it but Naruto learned it in a week. He s the only one ni the world who has been able to do that. Not only did he make a Wind Rasengan he created the Rasenshuriken & is skillfull enough to throw it at speeds so incredible that there is only one Shinobi who has dodged it, Third Raikage.
If that is not enough think about the fact that he is the only one in the show able to create so many clones which definitely shows how much mastery he has over chakra and how to equate it. Then if you think that Naruto isn't on his game with this chakra manipulation skill just remember how he is able to form a Rasenshuriken and Rasengan on his FINGER. Then he has been prasied by a BIJUU to have Mastered Chakra Manipulation even further than that of both of Naruto's parents.
So lets go over the facts shall we:
-Naruto can create a Rasengan which is the highest form Shape Manipulation. The Rasengan is based off the Bijuu Ball.
-Naruto can create a Bijuu Ball and use it with extreme precision. The Bijuu ball is the highest form of Charka Manipulation you can ever achieve. Now think abut if he ever fused this with his nature affinity!?
-Naruto not only created the Rasenshuriken by himself but also found a way to throw it and ignite it with by his will alone, which was suppose to be impossible.
-Naruto has created many variants of the Rasengan where as Sasuke has only created two.
-Naruto is able to create a Rasenshuriken on his finger and let m remind you that he has 10 fingers and 10 toes. lol
-Naruto can create a Bijuu Ball that is as strong as a combined Bijuu ball from 6 other Bijuus. He is also able to use Continuous Bijuu Balls.
-Naruto is also able to make a Bijuu Ball on his finger.
-Naruto is able to perfecty balance Senjutsu Chakra with his own.
-Naruto is able to fuse his chakra with Bijuu Chakra
-Naruto is able to give chakra to other people. He has mastered it to the point where he could mould the transferred chakra in order to adapt it to another person's specific chakra type.
Now Sasuke:
-He can create Chidori and many variants that all are very precise. Incredible in my book but no where near as fast as Rasenshuriken.
-He can controll the weather with his chakra and create Kirin.
-He can infuse his nature affinity with his sword to make it cut through anything
-He can make a lightning sword.
(most of these jutsus can be used by other Shinobi at the same level as Sasuke could use them)
-The most incredible thing that Sasuke can do is use Shape Manipulation in order to control his Amaterasu flames at will.
Yes a lot of Sasuke's jutsus looks cooler but Naruto's jutsus are all very powerful, very precise, and are mastered to the point where no one would ever get on his level(well not in this lifetime, not even Konohamaru).
