The 5070 has a special and very different feel, compared to the 5970.
Which is interesting is what you said about the yellow gold version.
I'm not a big fan of colored gold watches, but I surprised myself to have a pleasant look on the YG 5070...
The contrast between the black dial and the yellow gold case is interesting, very retro, charming.
I ended with a 5070G, but the YG is not to forget at the moment of the decision.
So, to answer your question, it will all depend on your " degree " of love for the 5070.
If, after having tested it, your heart beats strong and loud, it is not stupid to go for it ( it is never stupid to buy a watch you love ...
)
If not, well...
Best,
Nicolas