I am not able to advise on
Do you think that the 700 euros is worth it?
You would need to consider the benefit you get for your business against the extra cost.
What I can say though is that if you consider the performance gain and extra 2GB of graphics memory that is in the GTX 1070 compared to the GTX 1060, then I would (personally) always go for the most powerful system my budget can afford. Given that a laptop or PC has a useful life of two to three years, then the investment is something that is spread over that life.
Also, the GTX 1070 performance will translate in to improved FPS when building Scenes, and also and most importantly, a time savings when rendering.
Also, there is a big performance difference between a GTX 1070 and a GTX 1060. For laptops, even with the new GTX 1000 series, I would still always only go for the 1070 or preferably the 1080. Compare of course that, against what you have been doing, what you want to use the laptop for (primary design and visualizations, or more for presentation), and against the type of Lumion Scenes you generally work with (or hope to work with).
As a brand ASUS are fine. We tend to have more experience from users with the top performing brands of MSI and Alienware (Dell).
A read through the reviews also help to broaden your understanding of the differences for your decision. Although of course I find sometimes with lots of reviews on the net, it can be too much information much like my reply is becoming
Lastly, in comparison of the specs: the lowest (and hence cheapest) is the Notebook Asus ROG G502VM-FY071T 15.6. It has no SSD, is a GTX 1060 with 6GB memory, 16GB of RAM.
The next one up in price, Laptop Asus ROG G502VS-FY091T Gaming 15.6, adds a small 128GB but not really workable SSD for a Lumion environment, and for some reason less RAM at only 8GB, but with a GTX 1070. So the difference in price is the higher performing 1070 card, but 8GB of RAM is not recommended, at minimum it should be 16GB.
The most expensive, the Laptop Asus ROG G502VS-FY090T Gaming 15.6, has 16GB of RAM, a GTX 1070, an SSD increase to 256GB. Thats the best specs, but there's no flash sale on that product, so you are up for extra. Perhaps you could wait for a different sale or look elsewhere.
They all have the same CPU, so no difference there.
I would (where possible) look to increase RAM to 32GB, which the laptops support. But the added cost might be quite a lot. Adding extra RAM allows for more of the faster system memory to support the GTX 1070 memory once filled up. That translates in to better performance in Lumion for Scenes
that are more complex or have more higher resolution textures.
In summary, go for a GTX 1070. Perhaps look elsewhere for a better deal.
Please note that the above does not mean that I or Act-3D endorse specific products. We are unable to offer any guarantees regarding the expected performance in Lumion with the above-mentioned hardware, and you cannot hold us liable for any costs or damages incurred if you purchase hardware based on our posts on this forum or via email.