actually we don't know much about Hinata to decide who is better.
their chakra controll could be around the same level. med ninjutsu, Jyuuken also require excellent chakra control.
their speed is about the same too. I think Hinata is a bit faster, but that's sure both of them are slow...
we don't know who is the better strategist, but don't underestimate Hinata. we didn't see her full capacity yet.
both of them can kill with 1 blow (or at least capable of doing it)
BUT
Hinata's main role is fighting with her close combat techniques, when Sakura's is healing. It doesn't matter who taught who, not the teacher will decide who is better, only those who fight. keep this in mind.
also Sakura depending too much on her brute strength. if Hinata hit her arm and stop her chakra flow she is finished. same goes for Hinata, if she get a hit by Sakura it's ended.
about their fighting style. Hinata got training in the strongest taijutsu of the village, which is gives her more flexibility and strength. Sakura "only" got training by Tsunade, and for only to defend herself. if you watch carefully you can see her tactics is just charging at the enemy and punch hard. this is not so much against a Hyuuga.
I'm not saying Sakura hasn't a chance, but Hinata has more to win a battle between them.
*Jyuuken*, which is used to refer to a gentle fist type taijutsu, is a name given to a style used to name advanced users of the hyuugas KKG which hinata is not advanced at. There are similar martial arts, though the overuse of the idea of the chakra in the cartoon is a bit extreme.*
Hsing-i style and Pa qua style are the closest fighting styles to Jyuuken, and are interchangeable and often taught together. combined the two styles are about 90% the same as Jyuuken, right down to the use of eight trigrams, again, however, the idea of chakra in the anime is portrayed far more powerful than it actually is. Neji's fatal heart blow can not actually be performed with one strike, rather, five precise blows are necessary.
A good deal of Jyuuken, at least in Jyuuken Sentai Gekiranger, was based of of the beast system popular in kungfu, much in the same way that the four main styles of kungfu were the basis for Bending in Avatar: The Last Airbender. There*"is"*a Tiger Style (Jan, Dan) of kunfu, as well as a dragon style (Long). The others are blended versions of other styles, such as Gou's style, the primary base for it is Muay Thai, but are not outrightly those styles. The actual fighting style in Jyuuken Sentai Gekiranger is Kenpo, which is more or less translated as Beast Fist, further implies it's base in the beast system of kungfu. in saying so jyuuken is made up, hinata would surely lose to sakura due to the fact its not even real or and even so is only for advanced users of there eyes. do not forget sakura's teacher is the best close combat fighter. so my answer is sakura