Uzumaki + Hyuga is still inferior to Senju + Uchiha...
I think many make the mistake of assuming the Senju and Uchiha are -direct- genetic descendants. I do not believe this to be the case. It's far more probable that the Uzumaki and Senju each represent branches from another, more 'direct' line of genetic heritage. Saying one is superior or 'more pure' than the other is just silly.
That said - there is still no proof that the Hyuuga and Uchiha are related. While it is possible (and Kishimoto might migrate the plot in that direction now that Hinata has taken a more central stand), it is also possible that the Byakugan has other, separate, origins.
In some ways - I kind of hope it doesn't. While I may be beefing up the Byakugan in my fanfic... I really kind of like that it has not been plot-armored at all to the extent of the Sharingan. It represents a distinct tactical advantage - but it isn't over-powered compared to other specialized abilities of other clans. I'd rather not see Hinata come up with a never ending supply of moves named after deities.
Though I, honestly, don't think the "sage of six paths" is as simple as "Just get an Uchiha and Senju to hop in bed and out comes a Rinnegan!"
I mean - in real-world genetics, it's a ridiculous concept. The recombinant nature of our DNA makes brothers more genetically distinct from each other than the distinction that exists between races. We have, among the animal kingdom, some of the highest rates of per-generation genetic mutation (because we have one of the slower reproductive cycles and still have to keep up with all of the bacteria, viruses, etc out there). "Evolution" is not nearly as slow of a process as we once thought it was. As selective factors develop, individuals with the adaptation survive and become the image of that species. Several times throughout our history, the human population has been slashed to only a few thousand individuals world-wide (though only the most recent of such times is evident in our genetic heritage).
Which is all way beyond the interest of most people on NB.
In "Naruverse" genetics... the concept makes some sense. Though that would still just be too ideal to be taken seriously.
That said... Uzumaki chakra with Hyuuga Byakguan and fighting techniques would be somewhat of an unfair combination. I imagine the Byakugan would come in handy in developing the Rasengan - its viewing specialty more tailored to viewing chakra flow than capturing details of hand-signs.
I could see such offspring developing an entire art out of a hybrid of the Hyuuga's fighting style and the principles of the Rasengan ("Rasenarmor? ... Or perhaps a giant rasengan-style palm-revolving heaven - if such a thing would convey any kind of advantage). Not that the Uzumaki line is required for the rasengan... but their affinity for chakra supply would come in handy for such high-energy techniques.