For the story, It took me ages to find the right position with the little pyramid on left and big one on right, taking care about lights, etc. When everything went good, I finally had to wait around 10 minutes until tourists and my friends photographers go OUT the frame.
Back home, I've applied my usual workflow: photomatix + lightroom. That was a week ago. Finally tonight I tried the 32 bit HDR approach instead of the tonemapping.
With the 32 bit file, the picture remains clean and very sharp.You can also tweak it deeper, a bit like a RAW versus JPG. The tonemaped 16 bit file is more limited this way, but the exposition gets better with this solution.
When you rescale the both files at lower resolutions, these differences tend to be smaller. So about the choice to use one or another solution, it will mostly depend on the situation and your own taste.
If you want to compare the different results, you can check it right here.