The Pateks are a bit simpler in construction: only wheels based.
The Lange uses also bars or pins in theire movement.
As a rule: the simpler the better?
You decide as both will be pretty reliable.
Second technical advise: the Lange has much, much more potential.
From the looks point of view: the RG Lange IS THE CHOICE, if coloured metal is o.k. for you.
If WG: a bit bland, yes, but still a nice, small and thin watch.
Here the 5146 is a contender as also relatively thin and small.
All 5205 are more sporty, casual watches, nice, but not as versatile as the Lange or the 5146 are.
My personal choice: I simply flip a coin for either 5146 RG slate dial or Lange AC RG.
Best and let us please know what you went for.
Moritz