The design is always debatable, but technically the 5270 is a top inhouse movement.
It has a complex build minute counter, starts possibly much smoother and stops more accurately and is in flyback function much more
gentle to the movement.
I have to saz possibly smoother as I did not compare both and have to rely on literature.
I would choose this one, especially if I see that the second market is asking for the same price for a 5970 as for the 5270.
We are all different, but who is agreeing to such a deal???
There is only one flaw in the 5270 that I will not mention anymore, as I did quite often before.
Best
Moritz