So is Naruto...like father like son...Naruto may not be smart on the outside and rather slow on the uptake of complex stuff, but once in battle, his genius and techniques rival that of Shikamaru(a tad exaggerated...

) and the best of the ninjas...Moreover, if you really explain something and get it in his head, he improvises on what he understands at amazing speed, like when Kakashi teaches him of the experience learnt by the shadow clones...
BTW...plz. stop tagging Minato's name with rasengan already...just because he developed it doesnt mean he didnt have any other uber-cool jutsus up his sleeve..."that jutsu" might not have been anything to de with rasengan at all...for all we know it might turn out to be some sealing technique which Naruto learnt from Jiraiya(who in turn learnt it from his student, Minato)...