No arguments here...
Pichao. You have selected 2 nice watches - and I would say there are no quality, design, or technical arguments you can make for one over the other.
As you know, JLC and IWC share a very close tie with their parent company, and in the past there have also been a number of employees and designers who worked for both firms. From time-to-time there has also been some collaboration of movements, and sharing of components between the brands.
Your choice needs to come down to taste and preference. On one hand, you have the "rectangular" Reverso - with 2 dials. A fantastic concept, which you cannot compare to the IWC 3714. In the Portuguese, you have a chronograph, and idyllic, tradition-inspired Portuguese, large-format case design which may appeal to you.
As a brand, both IWC and JLC strive to deliver quality products with innovative designs - and as "sister companies" they are managed to bring "divergent" designs to market - because the parent company would not want one brand to cannibalize the revenues of the other.
it would be great for you to choose the IWC Portuguese Chrono - and we would welcome your posts of some photos and engage in discussion with us here.
Richard